16 files changed, 121 insertions, 376 deletions

diff --git a/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/ModelInitializer.java b/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/ModelInitializer.java
index 41b4fcb0..06b8ad77 100644
--- a/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/ModelInitializer.java
+++ b/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/ModelInitializer.java
@@ -44,8 +44,8 @@ public class ModelInitializer {
                         var isEqualsRelation = relation == builtinSymbols.equals();
                         var decisionTree = mergeAssertions(relationInfo, isEqualsRelation);
                         var defaultValue = isEqualsRelation ? TruthValue.FALSE : TruthValue.UNKNOWN;
-                        relationTrace.put(relation, new Symbol<>(relationInfo.name(), relationInfo.arity(), TruthValue.class, defaultValue
-                        ));
+                        relationTrace.put(relation, Symbol.of(
+                                        relationInfo.name(), relationInfo.arity(), TruthValue.class, defaultValue));
                 }
         }
 
diff --git a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/DiagonalQueryTest.java b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/DiagonalQueryTest.java
index 86a27f5b..b21c254c 100644
--- a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/DiagonalQueryTest.java
+++ b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/DiagonalQueryTest.java
@@ -11,6 +11,7 @@ import tools.refinery.store.query.ModelQueryAdapter;
 import tools.refinery.store.query.dnf.Dnf;
 import tools.refinery.store.query.dnf.Query;
 import tools.refinery.store.query.viatra.tests.QueryEngineTest;
+import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.FunctionView;
 import tools.refinery.store.query.view.KeyOnlyView;
 import tools.refinery.store.representation.Symbol;
@@ -26,13 +27,17 @@ import static tools.refinery.store.query.viatra.tests.QueryAssertions.assertNull
 import static tools.refinery.store.query.viatra.tests.QueryAssertions.assertResults;
 
 class DiagonalQueryTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Boolean> friend = Symbol.of("friend", 2);
+        private static final Symbol<Boolean> symbol = Symbol.of("symbol", 4);
+        private static final Symbol<Integer> intSymbol = Symbol.of("intSymbol", 4, Integer.class);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final AnySymbolView friendView = new KeyOnlyView<>(friend);
+        private static final AnySymbolView symbolView = new KeyOnlyView<>(symbol);
+        private static final AnySymbolView intSymbolView = new FunctionView<>(intSymbol);
+
         @QueryEngineTest
         void inputKeyNegationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 4, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new KeyOnlyView<>(symbol);
-
                 var query = Query.of("Diagonal", (builder, p1) -> builder.clause(p2 -> List.of(
                                 personView.call(p1),
                                 not(symbolView.call(p1, p1, p2, p2))
@@ -71,11 +76,6 @@ class DiagonalQueryTest {
 
         @QueryEngineTest
         void subQueryNegationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 4, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new KeyOnlyView<>(symbol);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -128,11 +128,6 @@ class DiagonalQueryTest {
 
         @QueryEngineTest
         void inputKeyCountTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 4, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new KeyOnlyView<>(symbol);
-
                 var query = Query.of("Diagonal", Integer.class, (builder, p1, output) -> builder.clause(p2 -> List.of(
                                 personView.call(p1),
                                 output.assign(symbolView.count(p1, p1, p2, p2))
@@ -172,11 +167,6 @@ class DiagonalQueryTest {
 
         @QueryEngineTest
         void subQueryCountTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 4, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new KeyOnlyView<>(symbol);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -230,19 +220,14 @@ class DiagonalQueryTest {
 
         @QueryEngineTest
         void inputKeyAggregationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 4, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new FunctionView<>(symbol);
-
                 var query = Query.of("Diagonal", Integer.class, (builder, p1, output) -> builder.clause(Integer.class,
                                 (p2, y) -> List.of(
                                                 personView.call(p1),
-                                                output.assign(symbolView.aggregate(y, INT_SUM, p1, p1, p2, p2, y))
+                                                output.assign(intSymbolView.aggregate(y, INT_SUM, p1, p1, p2, p2, y))
                                 )));
 
                 var store = ModelStore.builder()
-                                .symbols(person, symbol)
+                                .symbols(person, intSymbol)
                                 .with(ViatraModelQueryAdapter.builder()
                                                 .defaultHint(hint)
                                                 .queries(query))
@@ -250,7 +235,7 @@ class DiagonalQueryTest {
 
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);
-                var symbolInterpretation = model.getInterpretation(symbol);
+                var intSymbolInterpretation = model.getInterpretation(intSymbol);
                 var queryEngine = model.getAdapter(ModelQueryAdapter.class);
                 var queryResultSet = queryEngine.getResultSet(query);
 
@@ -258,11 +243,11 @@ class DiagonalQueryTest {
                 personInterpretation.put(Tuple.of(1), true);
                 personInterpretation.put(Tuple.of(2), true);
 
-                symbolInterpretation.put(Tuple.of(0, 0, 1, 1), 1);
-                symbolInterpretation.put(Tuple.of(0, 0, 2, 2), 2);
-                symbolInterpretation.put(Tuple.of(0, 0, 1, 2), 10);
-                symbolInterpretation.put(Tuple.of(1, 1, 0, 1), 11);
-                symbolInterpretation.put(Tuple.of(1, 2, 1, 1), 12);
+                intSymbolInterpretation.put(Tuple.of(0, 0, 1, 1), 1);
+                intSymbolInterpretation.put(Tuple.of(0, 0, 2, 2), 2);
+                intSymbolInterpretation.put(Tuple.of(0, 0, 1, 2), 10);
+                intSymbolInterpretation.put(Tuple.of(1, 1, 0, 1), 11);
+                intSymbolInterpretation.put(Tuple.of(1, 2, 1, 1), 12);
 
                 queryEngine.flushChanges();
                 assertNullableResults(Map.of(
@@ -275,11 +260,6 @@ class DiagonalQueryTest {
 
         @QueryEngineTest
         void subQueryAggregationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 4, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new FunctionView<>(symbol);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -289,12 +269,12 @@ class DiagonalQueryTest {
                         var y = builder.parameter("y", Integer.class);
                         builder.clause(
                                         personView.call(p1),
-                                        symbolView.call(p1, p2, p3, p4, x),
+                                        intSymbolView.call(p1, p2, p3, p4, x),
                                         y.assign(x)
                         );
                         builder.clause(
                                         personView.call(p2),
-                                        symbolView.call(p1, p2, p3, p4, x),
+                                        intSymbolView.call(p1, p2, p3, p4, x),
                                         y.assign(x)
                         );
                 });
@@ -305,7 +285,7 @@ class DiagonalQueryTest {
                                 )));
 
                 var store = ModelStore.builder()
-                                .symbols(person, symbol)
+                                .symbols(person, intSymbol)
                                 .with(ViatraModelQueryAdapter.builder()
                                                 .defaultHint(hint)
                                                 .queries(query))
@@ -313,7 +293,7 @@ class DiagonalQueryTest {
 
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);
-                var symbolInterpretation = model.getInterpretation(symbol);
+                var intSymbolInterpretation = model.getInterpretation(intSymbol);
                 var queryEngine = model.getAdapter(ModelQueryAdapter.class);
                 var queryResultSet = queryEngine.getResultSet(query);
 
@@ -321,11 +301,11 @@ class DiagonalQueryTest {
                 personInterpretation.put(Tuple.of(1), true);
                 personInterpretation.put(Tuple.of(2), true);
 
-                symbolInterpretation.put(Tuple.of(0, 0, 1, 1), 1);
-                symbolInterpretation.put(Tuple.of(0, 0, 2, 2), 2);
-                symbolInterpretation.put(Tuple.of(0, 0, 1, 2), 10);
-                symbolInterpretation.put(Tuple.of(1, 1, 0, 1), 11);
-                symbolInterpretation.put(Tuple.of(1, 2, 1, 1), 12);
+                intSymbolInterpretation.put(Tuple.of(0, 0, 1, 1), 1);
+                intSymbolInterpretation.put(Tuple.of(0, 0, 2, 2), 2);
+                intSymbolInterpretation.put(Tuple.of(0, 0, 1, 2), 10);
+                intSymbolInterpretation.put(Tuple.of(1, 1, 0, 1), 11);
+                intSymbolInterpretation.put(Tuple.of(1, 2, 1, 1), 12);
 
                 queryEngine.flushChanges();
                 assertNullableResults(Map.of(
@@ -338,18 +318,13 @@ class DiagonalQueryTest {
 
         @QueryEngineTest
         void inputKeyTransitiveTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 2, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new KeyOnlyView<>(symbol);
-
                 var query = Query.of("Diagonal", (builder, p1) -> builder.clause(
                                 personView.call(p1),
-                                symbolView.callTransitive(p1, p1)
+                                friendView.callTransitive(p1, p1)
                 ));
 
                 var store = ModelStore.builder()
-                                .symbols(person, symbol)
+                                .symbols(person, friend)
                                 .with(ViatraModelQueryAdapter.builder()
                                                 .defaultHint(hint)
                                                 .queries(query))
@@ -357,7 +332,7 @@ class DiagonalQueryTest {
 
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);
-                var symbolInterpretation = model.getInterpretation(symbol);
+                var friendInterpretation = model.getInterpretation(friend);
                 var queryEngine = model.getAdapter(ModelQueryAdapter.class);
                 var queryResultSet = queryEngine.getResultSet(query);
 
@@ -365,9 +340,9 @@ class DiagonalQueryTest {
                 personInterpretation.put(Tuple.of(1), true);
                 personInterpretation.put(Tuple.of(2), true);
 
-                symbolInterpretation.put(Tuple.of(0, 0), true);
-                symbolInterpretation.put(Tuple.of(0, 1), true);
-                symbolInterpretation.put(Tuple.of(1, 2), true);
+                friendInterpretation.put(Tuple.of(0, 0), true);
+                friendInterpretation.put(Tuple.of(0, 1), true);
+                friendInterpretation.put(Tuple.of(1, 2), true);
 
                 queryEngine.flushChanges();
                 assertResults(Map.of(
@@ -380,21 +355,16 @@ class DiagonalQueryTest {
 
         @QueryEngineTest
         void subQueryTransitiveTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var symbol = new Symbol<>("symbol", 2, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var symbolView = new KeyOnlyView<>(symbol);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
                         builder.clause(
                                         personView.call(p1),
-                                        symbolView.call(p1, p2)
+                                        friendView.call(p1, p2)
                         );
                         builder.clause(
                                         personView.call(p2),
-                                        symbolView.call(p1, p2)
+                                        friendView.call(p1, p2)
                         );
                 });
                 var query = Query.of("Diagonal", (builder, p1) -> builder.clause(
@@ -403,7 +373,7 @@ class DiagonalQueryTest {
                 ));
 
                 var store = ModelStore.builder()
-                                .symbols(person, symbol)
+                                .symbols(person, friend)
                                 .with(ViatraModelQueryAdapter.builder()
                                                 .defaultHint(hint)
                                                 .queries(query))
@@ -411,7 +381,7 @@ class DiagonalQueryTest {
 
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);
-                var symbolInterpretation = model.getInterpretation(symbol);
+                var friendInterpretation = model.getInterpretation(friend);
                 var queryEngine = model.getAdapter(ModelQueryAdapter.class);
                 var queryResultSet = queryEngine.getResultSet(query);
 
@@ -419,9 +389,9 @@ class DiagonalQueryTest {
                 personInterpretation.put(Tuple.of(1), true);
                 personInterpretation.put(Tuple.of(2), true);
 
-                symbolInterpretation.put(Tuple.of(0, 0), true);
-                symbolInterpretation.put(Tuple.of(0, 1), true);
-                symbolInterpretation.put(Tuple.of(1, 2), true);
+                friendInterpretation.put(Tuple.of(0, 0), true);
+                friendInterpretation.put(Tuple.of(0, 1), true);
+                friendInterpretation.put(Tuple.of(1, 2), true);
 
                 queryEngine.flushChanges();
                 assertResults(Map.of(
diff --git a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/FunctionalQueryTest.java b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/FunctionalQueryTest.java
index 98c8cd92..723e9180 100644
--- a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/FunctionalQueryTest.java
+++ b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/FunctionalQueryTest.java
@@ -13,6 +13,7 @@ import tools.refinery.store.query.dnf.Dnf;
 import tools.refinery.store.query.dnf.Query;
 import tools.refinery.store.query.term.Variable;
 import tools.refinery.store.query.viatra.tests.QueryEngineTest;
+import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.FilteredView;
 import tools.refinery.store.query.view.FunctionView;
 import tools.refinery.store.query.view.KeyOnlyView;
@@ -35,13 +36,15 @@ import static tools.refinery.store.query.viatra.tests.QueryAssertions.assertNull
 import static tools.refinery.store.query.viatra.tests.QueryAssertions.assertResults;
 
 class FunctionalQueryTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Integer> age = Symbol.of("age", 1, Integer.class);
+        private static final Symbol<TruthValue> friend = Symbol.of("friend", 2, TruthValue.class, TruthValue.FALSE);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final AnySymbolView ageView = new FunctionView<>(age);
+        private static final AnySymbolView friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
+
         @QueryEngineTest
         void inputKeyTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-
                 var query = Query.of("InputKey", Integer.class, (builder, p1, output) -> builder.clause(
                                 personView.call(p1),
                                 ageView.call(p1, output)
@@ -77,11 +80,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void predicateTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var x = builder.parameter("x", Integer.class);
@@ -125,11 +123,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void computationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-
                 var query = Query.of("Computation", Integer.class, (builder, p1, output) -> builder.clause(() -> {
                         var x = Variable.of("x", Integer.class);
                         return List.of(
@@ -168,11 +161,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void inputKeyCountTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var query = Query.of("Count", Integer.class, (builder, p1, output) -> builder.clause(
                                 personView.call(p1),
                                 output.assign(friendMustView.count(p1, Variable.of()))
@@ -210,11 +198,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void predicateCountTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -261,9 +244,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void inputKeyAggregationTest(QueryEvaluationHint hint) {
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var ageView = new FunctionView<>(age);
-
                 var query = Query.of("Aggregate", Integer.class, (builder, output) -> builder.clause(Integer.class,
                                 (y) -> List.of(output.assign(ageView.aggregate(y, INT_SUM, Variable.of(), y)))));
 
@@ -288,11 +268,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void predicateAggregationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var x = builder.parameter("x", Integer.class);
@@ -329,11 +304,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void extremeValueTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var subQuery = Dnf.of("SubQuery", builder -> {
                         var p1 = builder.parameter("p1");
                         var x = builder.parameter("x", Integer.class);
@@ -394,11 +364,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void invalidComputationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-
                 var query = Query.of("InvalidComputation", Integer.class,
                                 (builder, p1, output) -> builder.clause(Integer.class, (x) -> List.of(
                                                 personView.call(p1),
@@ -435,11 +400,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void invalidAssumeTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-
                 var query = Query.of("InvalidAssume", (builder, p1) -> builder.clause(Integer.class, (x) -> List.of(
                                 personView.call(p1),
                                 ageView.call(p1, x),
@@ -478,13 +438,6 @@ class FunctionalQueryTest {
 
         @QueryEngineTest
         void notFunctionalTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var query = Query.of("NotFunctional", Integer.class, (builder, p1, output) -> builder.clause((p2) -> List.of(
                                 personView.call(p1),
                                 friendMustView.call(p1, p2),
diff --git a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTest.java b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTest.java
index a9a2f71c..de0e6da1 100644
--- a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTest.java
+++ b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTest.java
@@ -13,6 +13,7 @@ import tools.refinery.store.query.dnf.Dnf;
 import tools.refinery.store.query.dnf.Query;
 import tools.refinery.store.query.term.Variable;
 import tools.refinery.store.query.viatra.tests.QueryEngineTest;
+import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.FilteredView;
 import tools.refinery.store.query.view.FunctionView;
 import tools.refinery.store.query.view.KeyOnlyView;
@@ -30,11 +31,14 @@ import static tools.refinery.store.query.term.int_.IntTerms.greaterEq;
 import static tools.refinery.store.query.viatra.tests.QueryAssertions.assertResults;
 
 class QueryTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<TruthValue> friend = Symbol.of("friend", 2, TruthValue.class, TruthValue.FALSE);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final AnySymbolView friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
+
         @QueryEngineTest
         void typeConstraintTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var asset = new Symbol<>("Asset", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
+                var asset = Symbol.of("Asset", 1);
 
                 var predicate = Query.of("TypeConstraint", (builder, p1) -> builder.clause(personView.call(p1)));
 
@@ -67,11 +71,6 @@ class QueryTest {
 
         @QueryEngineTest
         void relationConstraintTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var predicate = Query.of("RelationConstraint", (builder, p1, p2) -> builder.clause(
                                 personView.call(p1),
                                 personView.call(p2),
@@ -111,11 +110,6 @@ class QueryTest {
 
         @QueryEngineTest
         void existTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var predicate = Query.of("Exists", (builder, p1) -> builder.clause((p2) -> List.of(
                                 personView.call(p1),
                                 personView.call(p2),
@@ -155,12 +149,8 @@ class QueryTest {
 
         @QueryEngineTest
         void orTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var animal = new Symbol<>("Animal", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
+                var animal = Symbol.of("Animal", 1);
                 var animalView = new KeyOnlyView<>(animal);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
 
                 var predicate = Query.of("Or", (builder, p1, p2) -> builder.clause(
                                 personView.call(p1),
@@ -209,9 +199,6 @@ class QueryTest {
 
         @QueryEngineTest
         void equalityTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
                 var predicate = Query.of("Equality", (builder, p1, p2) -> builder.clause(
                                 personView.call(p1),
                                 personView.call(p2),
@@ -246,11 +233,6 @@ class QueryTest {
 
         @QueryEngineTest
         void inequalityTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var predicate = Query.of("Inequality", (builder, p1, p2, p3) -> builder.clause(
                                 personView.call(p1),
                                 personView.call(p2),
@@ -289,11 +271,6 @@ class QueryTest {
 
         @QueryEngineTest
         void patternCallTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var friendPredicate = Dnf.of("Friend", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -341,11 +318,6 @@ class QueryTest {
 
         @QueryEngineTest
         void negativeRelationViewTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var predicate = Query.of("NegativePatternCall", (builder, p1, p2) -> builder.clause(
                                 personView.call(p1),
                                 personView.call(p2),
@@ -390,11 +362,6 @@ class QueryTest {
 
         @QueryEngineTest
         void negativePatternCallTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var friendPredicate = Dnf.of("Friend", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -448,11 +415,6 @@ class QueryTest {
 
         @QueryEngineTest
         void negativeRelationViewWithQuantificationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var predicate = Query.of("Negative", (builder, p1) -> builder.clause(
                                 personView.call(p1),
                                 not(friendMustView.call(p1, Variable.of()))
@@ -489,11 +451,6 @@ class QueryTest {
 
         @QueryEngineTest
         void negativeWithQuantificationTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var called = Dnf.of("Called", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -539,11 +496,6 @@ class QueryTest {
 
         @QueryEngineTest
         void transitiveRelationViewTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var predicate = Query.of("Transitive", (builder, p1, p2) -> builder.clause(
                                 personView.call(p1),
                                 personView.call(p2),
@@ -587,11 +539,6 @@ class QueryTest {
 
         @QueryEngineTest
         void transitivePatternCallTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, TruthValue.class, TruthValue.FALSE);
-                var personView = new KeyOnlyView<>(person);
-                var friendMustView = new FilteredView<>(friend, "must", TruthValue::must);
-
                 var called = Dnf.of("Called", builder -> {
                         var p1 = builder.parameter("p1");
                         var p2 = builder.parameter("p2");
@@ -644,9 +591,7 @@ class QueryTest {
 
         @QueryEngineTest
         void assumeTest(QueryEvaluationHint hint) {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
+                var age = Symbol.of("age", 1, Integer.class);
                 var ageView = new FunctionView<>(age);
 
                 var query = Query.of("Constraint", (builder, p1) -> builder.clause(Integer.class, (x) -> List.of(
@@ -684,8 +629,6 @@ class QueryTest {
 
         @Test
         void alwaysFalseTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-
                 var predicate = Query.of("AlwaysFalse", builder -> builder.parameter("p1"));
 
                 var store = ModelStore.builder()
diff --git a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTransactionTest.java b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTransactionTest.java
index 6860ece9..66f043c6 100644
--- a/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTransactionTest.java
+++ b/subprojects/store-query-viatra/src/test/java/tools/refinery/store/query/viatra/QueryTransactionTest.java
@@ -11,6 +11,8 @@ import org.junit.jupiter.api.Test;
 import tools.refinery.store.model.ModelStore;
 import tools.refinery.store.query.ModelQueryAdapter;
 import tools.refinery.store.query.dnf.Query;
+import tools.refinery.store.query.dnf.RelationalQuery;
+import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.FilteredView;
 import tools.refinery.store.query.view.FunctionView;
 import tools.refinery.store.query.view.KeyOnlyView;
@@ -26,13 +28,15 @@ import static tools.refinery.store.query.viatra.tests.QueryAssertions.assertNull
 import static tools.refinery.store.query.viatra.tests.QueryAssertions.assertResults;
 
 class QueryTransactionTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Integer> age = Symbol.of("age", 1, Integer.class);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final AnySymbolView ageView = new FunctionView<>(age);
+        private static final RelationalQuery predicate = Query.of("TypeConstraint", (builder, p1) ->
+                        builder.clause(personView.call(p1)));
+
         @Test
         void flushTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
-                var predicate = Query.of("TypeConstraint", (builder, p1) -> builder.clause(personView.call(p1)));
-
                 var store = ModelStore.builder()
                                 .symbols(person)
                                 .with(ViatraModelQueryAdapter.builder()
@@ -95,11 +99,6 @@ class QueryTransactionTest {
 
         @Test
         void localSearchTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
-                var predicate = Query.of("TypeConstraint", (builder, p1) -> builder.clause(personView.call(p1)));
-
                 var store = ModelStore.builder()
                                 .symbols(person)
                                 .with(ViatraModelQueryAdapter.builder()
@@ -145,11 +144,7 @@ class QueryTransactionTest {
 
         @Test
         void unrelatedChangesTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var asset = new Symbol<>("Asset", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
-                var predicate = Query.of("TypeConstraint", (builder, p1) -> builder.clause(personView.call(p1)));
+                var asset = Symbol.of("Asset", 1);
 
                 var store = ModelStore.builder()
                                 .symbols(person, asset)
@@ -214,11 +209,6 @@ class QueryTransactionTest {
 
         @Test
         void tupleChangingChangeTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
-                var ageView = new FunctionView<>(age);
-
                 var query = Query.of("TypeConstraint", Integer.class, (builder, p1, output) -> builder.clause(
                                 personView.call(p1),
                                 ageView.call(p1, output)
@@ -256,9 +246,6 @@ class QueryTransactionTest {
 
         @Test
         void tuplePreservingUnchangedTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var personView = new KeyOnlyView<>(person);
                 var adultView = new FilteredView<>(age, "adult", n -> n != null && n >= 18);
 
                 var query = Query.of("TypeConstraint", (builder, p1) -> builder.clause(
@@ -299,11 +286,6 @@ class QueryTransactionTest {
         @Disabled("TODO Fix DiffCursor")
         @Test
         void commitAfterFlushTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
-                var predicate = Query.of("TypeConstraint", (builder, p1) -> builder.clause(personView.call(p1)));
-
                 var store = ModelStore.builder()
                                 .symbols(person)
                                 .with(ViatraModelQueryAdapter.builder()
@@ -353,11 +335,6 @@ class QueryTransactionTest {
         @Disabled("TODO Fix DiffCursor")
         @Test
         void commitWithoutFlushTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
-                var predicate = Query.of("TypeConstraint", (builder, p1) -> builder.clause(personView.call(p1)));
-
                 var store = ModelStore.builder()
                                 .symbols(person)
                                 .with(ViatraModelQueryAdapter.builder()
diff --git a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderLiteralEliminationTest.java b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderLiteralEliminationTest.java
index 687b06db..e17496e3 100644
--- a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderLiteralEliminationTest.java
+++ b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderLiteralEliminationTest.java
@@ -25,7 +25,7 @@ import static tools.refinery.store.query.literal.Literals.not;
 import static tools.refinery.store.query.tests.QueryMatchers.structurallyEqualTo;
 
 class DnfBuilderLiteralEliminationTest {
-        private final Symbol<Boolean> friend = new Symbol<>("friend", 2, Boolean.class, false);
+        private final Symbol<Boolean> friend = Symbol.of("friend", 2);
         private final SymbolView<Boolean> friendView = new KeyOnlyView<>(friend);
         private final NodeVariable p = Variable.of("p");
         private final NodeVariable q = Variable.of("q");
diff --git a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderVariableUnificationTest.java b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderVariableUnificationTest.java
index 4a85fe32..fc40c7b3 100644
--- a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderVariableUnificationTest.java
+++ b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfBuilderVariableUnificationTest.java
@@ -18,8 +18,8 @@ import static org.hamcrest.MatcherAssert.assertThat;
 import static tools.refinery.store.query.tests.QueryMatchers.structurallyEqualTo;
 
 class DnfBuilderVariableUnificationTest {
-        private final Symbol<Boolean> friend = new Symbol<>("friend", 2, Boolean.class, false);
-        private final Symbol<Boolean> children = new Symbol<>("children", 2, Boolean.class, false);
+        private final Symbol<Boolean> friend = Symbol.of("friend", 2);
+        private final Symbol<Boolean> children = Symbol.of("children", 2);
         private final SymbolView<Boolean> friendView = new KeyOnlyView<>(friend);
         private final SymbolView<Boolean> childrenView = new KeyOnlyView<>(children);
 
diff --git a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfToDefinitionStringTest.java b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfToDefinitionStringTest.java
index 63310a78..d75d7f17 100644
--- a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfToDefinitionStringTest.java
+++ b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/DnfToDefinitionStringTest.java
@@ -6,8 +6,10 @@
 package tools.refinery.store.query.dnf;
 
 import org.junit.jupiter.api.Test;
+import tools.refinery.store.query.term.NodeVariable;
 import tools.refinery.store.query.term.ParameterDirection;
 import tools.refinery.store.query.term.Variable;
+import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.KeyOnlyView;
 import tools.refinery.store.representation.Symbol;
 
@@ -16,9 +18,15 @@ import static org.hamcrest.Matchers.is;
 import static tools.refinery.store.query.literal.Literals.not;
 
 class DnfToDefinitionStringTest {
+        private static final Symbol<Boolean> person = Symbol.of("person", 1);
+        private static final Symbol<Boolean> friend = Symbol.of("friend", 2);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final AnySymbolView friendView = new KeyOnlyView<>(friend);
+        private static final NodeVariable p = Variable.of("p");
+        private static final NodeVariable q = Variable.of("q");
+
         @Test
         void noClausesTest() {
-                var p = Variable.of("p");
                 var dnf = Dnf.builder("Example").parameter(p).build();
 
                 assertThat(dnf.toDefinitionString(), is("""
@@ -39,7 +47,6 @@ class DnfToDefinitionStringTest {
 
         @Test
         void emptyClauseTest() {
-                var p = Variable.of("p");
                 var dnf = Dnf.builder("Example").parameter(p, ParameterDirection.IN).clause().build();
 
                 assertThat(dnf.toDefinitionString(), is("""
@@ -50,10 +57,6 @@ class DnfToDefinitionStringTest {
 
         @Test
         void relationViewPositiveTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
                 var dnf = Dnf.builder("Example").parameter(p).clause(friendView.call(p, q)).build();
 
                 assertThat(dnf.toDefinitionString(), is("""
@@ -64,10 +67,6 @@ class DnfToDefinitionStringTest {
 
         @Test
         void relationViewNegativeTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
                 var dnf = Dnf.builder("Example")
                                 .parameter(p, ParameterDirection.IN)
                                 .clause(not(friendView.call(p, q)))
@@ -81,10 +80,6 @@ class DnfToDefinitionStringTest {
 
         @Test
         void relationViewTransitiveTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
                 var dnf = Dnf.builder("Example").parameter(p).clause(friendView.callTransitive(p, q)).build();
 
                 assertThat(dnf.toDefinitionString(), is("""
@@ -95,10 +90,6 @@ class DnfToDefinitionStringTest {
 
         @Test
         void multipleParametersTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
                 var dnf = Dnf.builder("Example").parameters(p, q).clause(friendView.call(p, q)).build();
 
                 assertThat(dnf.toDefinitionString(), is("""
@@ -109,12 +100,6 @@ class DnfToDefinitionStringTest {
 
         @Test
         void multipleLiteralsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var person = new Symbol<>("person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
                 var dnf = Dnf.builder("Example")
                                 .parameter(p)
                                 .clause(
@@ -134,10 +119,6 @@ class DnfToDefinitionStringTest {
 
         @Test
         void multipleClausesTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
                 var dnf = Dnf.builder("Example")
                                 .parameter(p)
                                 .clause(friendView.call(p, q))
@@ -154,14 +135,8 @@ class DnfToDefinitionStringTest {
 
         @Test
         void dnfTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
                 var r = Variable.of("r");
                 var s = Variable.of("s");
-                var person = new Symbol<>("person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
                 var called  = Dnf.builder("Called").parameters(r, s).clause(friendView.call(r, s)).build();
                 var dnf = Dnf.builder("Example")
                                 .parameter(p)
diff --git a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/TopologicalSortTest.java b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/TopologicalSortTest.java
index 6d53f184..e22dbb21 100644
--- a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/TopologicalSortTest.java
+++ b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/TopologicalSortTest.java
@@ -21,7 +21,7 @@ import static tools.refinery.store.query.literal.Literals.not;
 import static tools.refinery.store.query.tests.QueryMatchers.structurallyEqualTo;
 
 class TopologicalSortTest {
-        private static final Symbol<Boolean> friend = new Symbol<>("friend", 2, Boolean.class, false);
+        private static final Symbol<Boolean> friend = Symbol.of("friend", 2);
         private static final AnySymbolView friendView = new KeyOnlyView<>(friend);
         private static final Dnf example = Dnf.of("example", builder -> {
                 var a = builder.parameter("a", ParameterDirection.IN);
diff --git a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/VariableDirectionTest.java b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/VariableDirectionTest.java
index 0a44664e..3608d09e 100644
--- a/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/VariableDirectionTest.java
+++ b/subprojects/store-query/src/test/java/tools/refinery/store/query/dnf/VariableDirectionTest.java
@@ -33,9 +33,9 @@ import static tools.refinery.store.query.literal.Literals.not;
 import static tools.refinery.store.query.term.int_.IntTerms.*;
 
 class VariableDirectionTest {
-        private static final Symbol<Boolean> person = new Symbol<>("Person", 1, Boolean.class, false);
-        private static final Symbol<Boolean> friend = new Symbol<>("friend", 2, Boolean.class, false);
-        private static final Symbol<Integer> age = new Symbol<>("age", 1, Integer.class, null);
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Boolean> friend = Symbol.of("friend", 2);
+        private static final Symbol<Integer> age = Symbol.of("age", 1, Integer.class);
         private static final AnySymbolView personView = new KeyOnlyView<>(person);
         private static final AnySymbolView friendView = new KeyOnlyView<>(friend);
         private static final AnySymbolView ageView = new FunctionView<>(age);
diff --git a/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToRawTest.java b/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToRawTest.java
index 07a55ff3..d447e99c 100644
--- a/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToRawTest.java
+++ b/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToRawTest.java
@@ -8,8 +8,10 @@ package tools.refinery.store.query.tests;
 import org.junit.jupiter.api.Test;
 import tools.refinery.store.query.dnf.Dnf;
 import tools.refinery.store.query.dnf.SymbolicParameter;
+import tools.refinery.store.query.term.NodeVariable;
 import tools.refinery.store.query.term.ParameterDirection;
 import tools.refinery.store.query.term.Variable;
+import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.KeyOnlyView;
 import tools.refinery.store.representation.Symbol;
 
@@ -22,13 +24,15 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 import static tools.refinery.store.query.tests.QueryMatchers.structurallyEqualTo;
 
 class StructurallyEqualToRawTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Boolean> friend = Symbol.of("friend", 2);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final AnySymbolView friendView = new KeyOnlyView<>(friend);
+        private static final NodeVariable p = Variable.of("p");
+        private static final NodeVariable q = Variable.of("q");
+
         @Test
         void flatEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
                 var actual = Dnf.builder("Actual").parameters(p).clause(personView.call(p)).build();
 
                 assertThat(actual, structurallyEqualTo(
@@ -39,11 +43,6 @@ class StructurallyEqualToRawTest {
 
         @Test
         void flatNotEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var actual = Dnf.builder("Actual").parameters(p).clause(friendView.call(p, q)).build();
 
                 var assertion = structurallyEqualTo(
@@ -55,11 +54,6 @@ class StructurallyEqualToRawTest {
 
         @Test
         void deepEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
                 var actual = Dnf.builder("Actual").parameters(q).clause(
                                 Dnf.builder("Actual2").parameters(p).clause(personView.call(p)).build().call(q)
                 ).build();
@@ -76,11 +70,6 @@ class StructurallyEqualToRawTest {
 
         @Test
         void deepNotEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var actual = Dnf.builder("Actual").parameter(q).clause(
                                 Dnf.builder("Actual2").parameters(p).clause(friendView.call(p, q)).build().call(q)
                 ).build();
@@ -103,11 +92,6 @@ class StructurallyEqualToRawTest {
 
         @Test
         void parameterListLengthMismatchTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var actual = Dnf.builder("Actual").parameters(p, q).clause(
                                 friendView.call(p, q)
                 ).build();
@@ -122,10 +106,6 @@ class StructurallyEqualToRawTest {
 
         @Test
         void parameterDirectionMismatchTest() {
-                var p = Variable.of("p");
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
                 var actual = Dnf.builder("Actual").parameter(p, ParameterDirection.IN).clause(
                                 personView.call(p)
                 ).build();
@@ -140,11 +120,6 @@ class StructurallyEqualToRawTest {
 
         @Test
         void clauseCountMismatchTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var actual = Dnf.builder("Actual").parameters(p, q).clause(
                                 friendView.call(p, q)
                 ).build();
@@ -165,11 +140,6 @@ class StructurallyEqualToRawTest {
 
         @Test
         void literalCountMismatchTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var actual = Dnf.builder("Actual").parameters(p, q).clause(
                                 friendView.call(p, q)
                 ).build();
diff --git a/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToTest.java b/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToTest.java
index e2983a3a..f716b805 100644
--- a/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToTest.java
+++ b/subprojects/store-query/src/test/java/tools/refinery/store/query/tests/StructurallyEqualToTest.java
@@ -7,8 +7,10 @@ package tools.refinery.store.query.tests;
 
 import org.junit.jupiter.api.Test;
 import tools.refinery.store.query.dnf.Dnf;
+import tools.refinery.store.query.term.NodeVariable;
 import tools.refinery.store.query.term.ParameterDirection;
 import tools.refinery.store.query.term.Variable;
+import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.KeyOnlyView;
 import tools.refinery.store.representation.Symbol;
 
@@ -18,13 +20,15 @@ import static org.junit.jupiter.api.Assertions.assertThrows;
 import static tools.refinery.store.query.tests.QueryMatchers.structurallyEqualTo;
 
 class StructurallyEqualToTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Boolean> friend = Symbol.of("friend", 2);
+        private static final AnySymbolView personView = new KeyOnlyView<>(person);
+        private static final AnySymbolView friendView = new KeyOnlyView<>(friend);
+        private static final NodeVariable p = Variable.of("p");
+        private static final NodeVariable q = Variable.of("q");
+
         @Test
         void flatEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
                 var expected = Dnf.builder("Expected").parameters(q).clause(personView.call(q)).build();
                 var actual = Dnf.builder("Actual").parameters(p).clause(personView.call(p)).build();
 
@@ -33,11 +37,6 @@ class StructurallyEqualToTest {
 
         @Test
         void flatNotEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var expected = Dnf.builder("Expected").parameters(q).clause(friendView.call(q, q)).build();
                 var actual = Dnf.builder("Actual").parameters(p).clause(friendView.call(p, q)).build();
 
@@ -47,11 +46,6 @@ class StructurallyEqualToTest {
 
         @Test
         void deepEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
                 var expected = Dnf.builder("Expected").parameters(q).clause(
                                 Dnf.builder("Expected2").parameters(p).clause(personView.call(p)).build().call(q)
                 ).build();
@@ -64,11 +58,6 @@ class StructurallyEqualToTest {
 
         @Test
         void deepNotEqualsTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var expected = Dnf.builder("Expected").parameters(q).clause(
                                 Dnf.builder("Expected2").parameters(p).clause(friendView.call(p, p)).build().call(q)
                 ).build();
@@ -83,11 +72,6 @@ class StructurallyEqualToTest {
 
         @Test
         void parameterListLengthMismatchTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var expected = Dnf.builder("Expected").parameter(p).clause(
                                 friendView.call(p, p)
                 ).build();
@@ -101,10 +85,6 @@ class StructurallyEqualToTest {
 
         @Test
         void parameterDirectionMismatchTest() {
-                var p = Variable.of("p");
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var personView = new KeyOnlyView<>(person);
-
                 var expected = Dnf.builder("Expected").parameter(p, ParameterDirection.OUT).clause(
                                 personView.call(p)
                 ).build();
@@ -118,11 +98,6 @@ class StructurallyEqualToTest {
 
         @Test
         void clauseCountMismatchTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var expected = Dnf.builder("Expected")
                                 .parameters(p, q)
                                 .clause(friendView.call(p, q))
@@ -138,11 +113,6 @@ class StructurallyEqualToTest {
 
         @Test
         void literalCountMismatchTest() {
-                var p = Variable.of("p");
-                var q = Variable.of("q");
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-                var friendView = new KeyOnlyView<>(friend);
-
                 var expected = Dnf.builder("Expected").parameters(p, q).clause(
                                 friendView.call(p, q),
                                 friendView.call(q, p)
diff --git a/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/base/BaseDecisionTranslationUnit.java b/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/base/BaseDecisionTranslationUnit.java
index 405e58ac..a1e4b816 100644
--- a/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/base/BaseDecisionTranslationUnit.java
+++ b/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/base/BaseDecisionTranslationUnit.java
@@ -29,7 +29,7 @@ public class BaseDecisionTranslationUnit extends TranslationUnit {
                 }
                 this.partialRelation = partialRelation;
                 this.seed = seed;
-                symbol = new Symbol<>(partialRelation.name(), partialRelation.arity(), TruthValue.class, TruthValue.UNKNOWN);
+                symbol = Symbol.of(partialRelation.name(), partialRelation.arity(), TruthValue.class, TruthValue.UNKNOWN);
         }
 
         public BaseDecisionTranslationUnit(PartialRelation partialRelation) {
diff --git a/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/typehierarchy/TypeHierarchyTranslationUnit.java b/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/typehierarchy/TypeHierarchyTranslationUnit.java
index e1aa2014..06e3c05f 100644
--- a/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/typehierarchy/TypeHierarchyTranslationUnit.java
+++ b/subprojects/store-reasoning/src/main/java/tools/refinery/store/reasoning/translator/typehierarchy/TypeHierarchyTranslationUnit.java
@@ -16,8 +16,8 @@ import java.util.List;
 import java.util.Map;
 
 public class TypeHierarchyTranslationUnit extends TranslationUnit {
-        static final Symbol<InferredType> INFERRED_TYPE_SYMBOL = new Symbol<>("inferredType", 1,
-                        InferredType.class, InferredType.UNTYPED);
+        static final Symbol<InferredType> INFERRED_TYPE_SYMBOL = Symbol.of(
+                        "inferredType", 1, InferredType.class, InferredType.UNTYPED);
 
         private final TypeAnalyzer typeAnalyzer;
 
diff --git a/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java b/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java
index aad88921..cc748180 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/representation/Symbol.java
@@ -7,18 +7,19 @@ package tools.refinery.store.representation;
 
 public record Symbol<T>(String name, int arity, Class<T> valueType, T defaultValue) implements AnySymbol {
         @Override
-        public boolean equals(Object o) {
-                return this == o;
+        public String toString() {
+                return "%s/%d".formatted(name, arity);
         }
 
-        @Override
-        public int hashCode() {
-                // Compare by identity to make hash table lookups more efficient.
-                return System.identityHashCode(this);
+        public static Symbol<Boolean> of(String name, int arity) {
+                return of(name, arity, Boolean.class, false);
         }
 
-        @Override
-        public String toString() {
-                return "%s/%d".formatted(name, arity);
+        public static <T> Symbol<T> of(String name, int arity, Class<T> valueType) {
+                return of(name, arity, valueType, null);
+        }
+
+        public static <T> Symbol<T> of(String name, int arity, Class<T> valueType, T defaultValue) {
+                return new Symbol<>(name, arity, valueType, defaultValue);
         }
 }
diff --git a/subprojects/store/src/test/java/tools/refinery/store/model/tests/ModelTest.java b/subprojects/store/src/test/java/tools/refinery/store/model/tests/ModelTest.java
index 1017ff28..56b75804 100644
--- a/subprojects/store/src/test/java/tools/refinery/store/model/tests/ModelTest.java
+++ b/subprojects/store/src/test/java/tools/refinery/store/model/tests/ModelTest.java
@@ -14,27 +14,24 @@ import tools.refinery.store.tuple.Tuple;
 import static org.junit.jupiter.api.Assertions.*;
 
 class ModelTest {
+        private static final Symbol<Boolean> person = Symbol.of("Person", 1);
+        private static final Symbol<Integer> age = Symbol.of("age", 1, Integer.class);
+        private static final Symbol<Boolean> friend = Symbol.of("friend", 2);
+
         @Test
         void modelConstructionTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-
                 var store = ModelStore.builder().symbols(person, friend).build();
                 var symbols = store.getSymbols();
 
                 assertTrue(symbols.contains(person));
                 assertTrue(symbols.contains(friend));
 
-                var other = new Symbol<>("other", 2, Integer.class, null);
+                var other = Symbol.of("other", 2, Integer.class);
                 assertFalse(symbols.contains(other));
         }
 
         @Test
         void modelBuildingTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-
                 var store = ModelStore.builder().symbols(person, age, friend).build();
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);
@@ -62,8 +59,6 @@ class ModelTest {
 
         @Test
         void modelBuildingArityFailTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-
                 var store = ModelStore.builder().symbols(person).build();
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);
@@ -75,8 +70,6 @@ class ModelTest {
 
         @Test
         void modelBuildingNullFailTest() {
-                var age = new Symbol<>("age", 1, Integer.class, null);
-
                 var store = ModelStore.builder().symbols(age).build();
                 var model = store.createEmptyModel();
                 var ageInterpretation = model.getInterpretation(age);
@@ -89,10 +82,6 @@ class ModelTest {
 
         @Test
         void modelUpdateTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var age = new Symbol<>("age", 1, Integer.class, null);
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-
                 var store = ModelStore.builder().symbols(person, age, friend).build();
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);
@@ -118,9 +107,6 @@ class ModelTest {
 
         @Test
         void restoreTest() {
-                var person = new Symbol<>("Person", 1, Boolean.class, false);
-                var friend = new Symbol<>("friend", 2, Boolean.class, false);
-
                 var store = ModelStore.builder().symbols(person, friend).build();
                 var model = store.createEmptyModel();
                 var personInterpretation = model.getInterpretation(person);