24 files changed, 256 insertions, 113 deletions

diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/QueryInterpreterBuilder.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/QueryInterpreterBuilder.java
index 6e167d0d..010164e2 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/QueryInterpreterBuilder.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/QueryInterpreterBuilder.java
@@ -7,9 +7,9 @@ package tools.refinery.store.query.interpreter;
 
 import tools.refinery.store.model.ModelStore;
 import tools.refinery.store.query.ModelQueryBuilder;
-import tools.refinery.store.query.dnf.AnyQuery;
-import tools.refinery.store.query.dnf.Dnf;
-import tools.refinery.store.query.rewriter.DnfRewriter;
+import tools.refinery.logic.dnf.AnyQuery;
+import tools.refinery.logic.dnf.Dnf;
+import tools.refinery.logic.rewriter.DnfRewriter;
 import tools.refinery.interpreter.api.InterpreterEngineOptions;
 import tools.refinery.interpreter.matchers.backend.IQueryBackendFactory;
 import tools.refinery.interpreter.matchers.backend.QueryEvaluationHint;
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterAdapterImpl.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterAdapterImpl.java
index ee527fd3..c5423223 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterAdapterImpl.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterAdapterImpl.java
@@ -7,10 +7,10 @@ package tools.refinery.store.query.interpreter.internal;
 
 import tools.refinery.store.model.Model;
 import tools.refinery.store.model.ModelListener;
-import tools.refinery.store.query.dnf.AnyQuery;
-import tools.refinery.store.query.dnf.FunctionalQuery;
-import tools.refinery.store.query.dnf.Query;
-import tools.refinery.store.query.dnf.RelationalQuery;
+import tools.refinery.logic.dnf.AnyQuery;
+import tools.refinery.logic.dnf.FunctionalQuery;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.dnf.RelationalQuery;
 import tools.refinery.store.query.resultset.AnyResultSet;
 import tools.refinery.store.query.resultset.EmptyResultSet;
 import tools.refinery.store.query.resultset.ResultSet;
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterBuilderImpl.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterBuilderImpl.java
index 4e839b43..1791e626 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterBuilderImpl.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterBuilderImpl.java
@@ -9,12 +9,12 @@ import org.eclipse.emf.ecore.EPackage;
 import tools.refinery.interpreter.rete.recipes.RecipesPackage;
 import tools.refinery.store.adapter.AbstractModelAdapterBuilder;
 import tools.refinery.store.model.ModelStore;
-import tools.refinery.store.query.dnf.AnyQuery;
-import tools.refinery.store.query.dnf.Dnf;
-import tools.refinery.store.query.rewriter.CompositeRewriter;
-import tools.refinery.store.query.rewriter.DnfRewriter;
-import tools.refinery.store.query.rewriter.DuplicateDnfRemover;
-import tools.refinery.store.query.rewriter.InputParameterResolver;
+import tools.refinery.logic.dnf.AnyQuery;
+import tools.refinery.logic.dnf.Dnf;
+import tools.refinery.logic.rewriter.CompositeRewriter;
+import tools.refinery.logic.rewriter.DnfRewriter;
+import tools.refinery.logic.rewriter.DuplicateDnfRemover;
+import tools.refinery.logic.rewriter.InputParameterResolver;
 import tools.refinery.store.query.interpreter.QueryInterpreterBuilder;
 import tools.refinery.store.query.interpreter.internal.localsearch.FlatCostFunction;
 import tools.refinery.store.query.interpreter.internal.matcher.RawPatternMatcher;
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterStoreAdapterImpl.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterStoreAdapterImpl.java
index 10e7a402..d1ec3e3e 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterStoreAdapterImpl.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/QueryInterpreterStoreAdapterImpl.java
@@ -11,8 +11,8 @@ import tools.refinery.interpreter.api.InterpreterEngineOptions;
 import tools.refinery.interpreter.matchers.context.IInputKey;
 import tools.refinery.store.model.Model;
 import tools.refinery.store.model.ModelStore;
-import tools.refinery.store.query.dnf.AnyQuery;
-import tools.refinery.store.query.dnf.Query;
+import tools.refinery.logic.dnf.AnyQuery;
+import tools.refinery.logic.dnf.Query;
 import tools.refinery.store.query.interpreter.QueryInterpreterStoreAdapter;
 import tools.refinery.store.query.interpreter.internal.matcher.RawPatternMatcher;
 import tools.refinery.store.query.view.AnySymbolView;
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/context/RelationalQueryMetaContext.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/context/RelationalQueryMetaContext.java
index 2b1ff2b4..117e81ba 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/context/RelationalQueryMetaContext.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/context/RelationalQueryMetaContext.java
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ * SPDX-FileCopyrightText: 2021-2024 The Refinery Authors <https://refinery.tools/>
  *
  * SPDX-License-Identifier: EPL-2.0
  */
@@ -48,7 +48,7 @@ public class RelationalQueryMetaContext extends AbstractQueryMetaContext {
                 }
                 var symbolView = checkKey(implyingKey);
                 var relationViewImplications = symbolView.getImpliedRelationViews();
-                var inputKeyImplications = new HashSet<InputKeyImplication>(relationViewImplications.size());
+                var inputKeyImplications = HashSet.<InputKeyImplication>newHashSet(relationViewImplications.size());
                 for (var relationViewImplication : relationViewImplications) {
                         if (!symbolView.equals(relationViewImplication.implyingView())) {
                                 throw new IllegalArgumentException("Relation view %s returned unrelated implication %s".formatted(
@@ -82,7 +82,7 @@ public class RelationalQueryMetaContext extends AbstractQueryMetaContext {
                 }
                 var relationView = checkKey(key);
                 var functionalDependencies = relationView.getFunctionalDependencies();
-                var flattened = new HashMap<Set<Integer>, Set<Integer>>(functionalDependencies.size());
+                var flattened = HashMap.<Set<Integer>, Set<Integer>>newHashMap(functionalDependencies.size());
                 for (var functionalDependency : functionalDependencies) {
                         var forEach = functionalDependency.forEach();
                         checkValidIndices(relationView, forEach);
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/AbstractInterpretedMatcher.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/AbstractInterpretedMatcher.java
index 8cec0bf6..8e6a74ed 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/AbstractInterpretedMatcher.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/AbstractInterpretedMatcher.java
@@ -7,7 +7,7 @@ package tools.refinery.store.query.interpreter.internal.matcher;
 
 import tools.refinery.interpreter.matchers.backend.IQueryResultProvider;
 import tools.refinery.interpreter.matchers.backend.IUpdateable;
-import tools.refinery.store.query.dnf.Query;
+import tools.refinery.logic.dnf.Query;
 import tools.refinery.store.query.resultset.AbstractResultSet;
 import tools.refinery.store.query.interpreter.internal.QueryInterpreterAdapterImpl;
 
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedFunctionalMatcher.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedFunctionalMatcher.java
index 249664a4..bf707487 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedFunctionalMatcher.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedFunctionalMatcher.java
@@ -11,7 +11,7 @@ import tools.refinery.interpreter.matchers.tuple.Tuples;
 import tools.refinery.interpreter.rete.index.IterableIndexer;
 import tools.refinery.interpreter.rete.matcher.RetePatternMatcher;
 import tools.refinery.store.map.Cursor;
-import tools.refinery.store.query.dnf.FunctionalQuery;
+import tools.refinery.logic.dnf.FunctionalQuery;
 import tools.refinery.store.query.interpreter.internal.QueryInterpreterAdapterImpl;
 import tools.refinery.store.tuple.Tuple;
 
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedRelationalMatcher.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedRelationalMatcher.java
index 9278b46d..9d9c3042 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedRelationalMatcher.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/matcher/InterpretedRelationalMatcher.java
@@ -12,7 +12,7 @@ import tools.refinery.interpreter.rete.index.Indexer;
 import tools.refinery.interpreter.rete.matcher.RetePatternMatcher;
 import tools.refinery.store.map.Cursor;
 import tools.refinery.store.map.Cursors;
-import tools.refinery.store.query.dnf.RelationalQuery;
+import tools.refinery.logic.dnf.RelationalQuery;
 import tools.refinery.store.query.interpreter.internal.QueryInterpreterAdapterImpl;
 import tools.refinery.store.tuple.Tuple;
 
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/CheckEvaluator.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/CheckEvaluator.java
index 4a71e879..8cfc2226 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/CheckEvaluator.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/CheckEvaluator.java
@@ -6,7 +6,7 @@
 package tools.refinery.store.query.interpreter.internal.pquery;
 
 import tools.refinery.interpreter.matchers.psystem.IValueProvider;
-import tools.refinery.store.query.term.Term;
+import tools.refinery.logic.term.Term;
 
 class CheckEvaluator extends TermEvaluator<Boolean> {
         public CheckEvaluator(Term<Boolean> term) {
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/Dnf2PQuery.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/Dnf2PQuery.java
index 24205cf4..0ffaa6b2 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/Dnf2PQuery.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/Dnf2PQuery.java
@@ -1,25 +1,10 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ * SPDX-FileCopyrightText: 2021-2024 The Refinery Authors <https://refinery.tools/>
  *
  * SPDX-License-Identifier: EPL-2.0
  */
 package tools.refinery.store.query.interpreter.internal.pquery;
 
-import tools.refinery.interpreter.matchers.psystem.annotations.ParameterReference;
-import tools.refinery.interpreter.matchers.psystem.basicdeferred.*;
-import tools.refinery.interpreter.matchers.psystem.basicenumerables.*;
-import tools.refinery.interpreter.matchers.psystem.basicenumerables.Connectivity;
-import tools.refinery.store.query.Constraint;
-import tools.refinery.store.query.dnf.Dnf;
-import tools.refinery.store.query.dnf.DnfClause;
-import tools.refinery.store.query.dnf.SymbolicParameter;
-import tools.refinery.store.query.literal.*;
-import tools.refinery.store.query.term.ConstantTerm;
-import tools.refinery.store.query.term.StatefulAggregator;
-import tools.refinery.store.query.term.StatelessAggregator;
-import tools.refinery.store.query.term.Variable;
-import tools.refinery.store.query.view.AnySymbolView;
-import tools.refinery.store.util.CycleDetectingMapper;
 import tools.refinery.interpreter.matchers.backend.IQueryBackendFactory;
 import tools.refinery.interpreter.matchers.backend.QueryEvaluationHint;
 import tools.refinery.interpreter.matchers.context.IInputKey;
@@ -28,11 +13,27 @@ import tools.refinery.interpreter.matchers.psystem.PVariable;
 import tools.refinery.interpreter.matchers.psystem.aggregations.BoundAggregator;
 import tools.refinery.interpreter.matchers.psystem.aggregations.IMultisetAggregationOperator;
 import tools.refinery.interpreter.matchers.psystem.annotations.PAnnotation;
+import tools.refinery.interpreter.matchers.psystem.annotations.ParameterReference;
+import tools.refinery.interpreter.matchers.psystem.basicdeferred.*;
+import tools.refinery.interpreter.matchers.psystem.basicenumerables.Connectivity;
+import tools.refinery.interpreter.matchers.psystem.basicenumerables.*;
 import tools.refinery.interpreter.matchers.psystem.queries.PParameter;
 import tools.refinery.interpreter.matchers.psystem.queries.PParameterDirection;
 import tools.refinery.interpreter.matchers.psystem.queries.PQuery;
 import tools.refinery.interpreter.matchers.tuple.Tuple;
 import tools.refinery.interpreter.matchers.tuple.Tuples;
+import tools.refinery.logic.Constraint;
+import tools.refinery.logic.dnf.Dnf;
+import tools.refinery.logic.dnf.DnfClause;
+import tools.refinery.logic.dnf.FunctionalDependency;
+import tools.refinery.logic.dnf.SymbolicParameter;
+import tools.refinery.logic.literal.*;
+import tools.refinery.logic.term.ConstantTerm;
+import tools.refinery.logic.term.StatefulAggregator;
+import tools.refinery.logic.term.StatelessAggregator;
+import tools.refinery.logic.term.Variable;
+import tools.refinery.logic.util.CycleDetectingMapper;
+import tools.refinery.store.query.view.AnySymbolView;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -79,15 +80,7 @@ public class Dnf2PQuery {
                 pQuery.setParameters(parameterList);
 
                 for (var functionalDependency : dnfQuery.getFunctionalDependencies()) {
-                        var functionalDependencyAnnotation = new PAnnotation("FunctionalDependency");
-                        for (var forEachVariable : functionalDependency.forEach()) {
-                                var reference = new ParameterReference(forEachVariable.getUniqueName());
-                                functionalDependencyAnnotation.addAttribute("forEach", reference);
-                        }
-                        for (var uniqueVariable : functionalDependency.unique()) {
-                                var reference = new ParameterReference(uniqueVariable.getUniqueName());
-                                functionalDependencyAnnotation.addAttribute("unique", reference);
-                        }
+                        var functionalDependencyAnnotation = getFunctionalDependencyAnnotation(functionalDependency);
                         pQuery.addAnnotation(functionalDependencyAnnotation);
                 }
 
@@ -108,26 +101,33 @@ public class Dnf2PQuery {
                 return pQuery;
         }
 
-        private void translateLiteral(Literal literal, PBody body) {
-                if (literal instanceof EquivalenceLiteral equivalenceLiteral) {
-                        translateEquivalenceLiteral(equivalenceLiteral, body);
-                } else if (literal instanceof CallLiteral callLiteral) {
-                        translateCallLiteral(callLiteral, body);
-                } else if (literal instanceof ConstantLiteral constantLiteral) {
-                        translateConstantLiteral(constantLiteral, body);
-                } else if (literal instanceof AssignLiteral<?> assignLiteral) {
-                        translateAssignLiteral(assignLiteral, body);
-                } else if (literal instanceof CheckLiteral checkLiteral) {
-                        translateCheckLiteral(checkLiteral, body);
-                } else if (literal instanceof CountLiteral countLiteral) {
-                        translateCountLiteral(countLiteral, body);
-                } else if (literal instanceof AggregationLiteral<?, ?> aggregationLiteral) {
-                        translateAggregationLiteral(aggregationLiteral, body);
-                } else if (literal instanceof RepresentativeElectionLiteral representativeElectionLiteral) {
-                        translateRepresentativeElectionLiteral(representativeElectionLiteral, body);
-                } else {
-                        throw new IllegalArgumentException("Unknown literal: " + literal.toString());
+        private static PAnnotation getFunctionalDependencyAnnotation(FunctionalDependency<Variable> functionalDependency) {
+                var functionalDependencyAnnotation = new PAnnotation("FunctionalDependency");
+                for (var forEachVariable : functionalDependency.forEach()) {
+                        var reference = new ParameterReference(forEachVariable.getUniqueName());
+                        functionalDependencyAnnotation.addAttribute("forEach", reference);
                 }
+                for (var uniqueVariable : functionalDependency.unique()) {
+                        var reference = new ParameterReference(uniqueVariable.getUniqueName());
+                        functionalDependencyAnnotation.addAttribute("unique", reference);
+                }
+                return functionalDependencyAnnotation;
+        }
+
+        private void translateLiteral(Literal literal, PBody body) {
+        switch (literal) {
+            case EquivalenceLiteral equivalenceLiteral -> translateEquivalenceLiteral(equivalenceLiteral, body);
+            case CallLiteral callLiteral -> translateCallLiteral(callLiteral, body);
+            case ConstantLiteral constantLiteral -> translateConstantLiteral(constantLiteral, body);
+            case AssignLiteral<?> assignLiteral -> translateAssignLiteral(assignLiteral, body);
+            case CheckLiteral checkLiteral -> translateCheckLiteral(checkLiteral, body);
+            case CountLiteral countLiteral -> translateCountLiteral(countLiteral, body);
+            case AggregationLiteral<?, ?> aggregationLiteral -> translateAggregationLiteral(aggregationLiteral, body);
+                        case LeftJoinLiteral<?> leftJoinLiteral -> translateLeftJoinLiteral(leftJoinLiteral, body);
+            case RepresentativeElectionLiteral representativeElectionLiteral ->
+                    translateRepresentativeElectionLiteral(representativeElectionLiteral, body);
+            case null, default -> throw new IllegalArgumentException("Unknown literal: " + literal);
+        }
         }
 
         private void translateEquivalenceLiteral(EquivalenceLiteral equivalenceLiteral, PBody body) {
@@ -244,6 +244,21 @@ public class Dnf2PQuery {
                                 aggregatedColumn);
         }
 
+        private <T> void translateLeftJoinLiteral(LeftJoinLiteral<T> leftJoinLiteral, PBody body) {
+                var wrappedCall = wrapperFactory.maybeWrapConstraint(leftJoinLiteral);
+                var substitution = translateSubstitution(wrappedCall.remappedArguments(), body);
+                var placeholderVariable = body.getOrCreateVariableByName(
+                                leftJoinLiteral.getPlaceholderVariable().getUniqueName());
+                var optionalColumn = substitution.invertIndex().get(placeholderVariable);
+                if (optionalColumn == null) {
+                        throw new IllegalStateException("Placeholder variable %s not found in substitution %s"
+                                        .formatted(placeholderVariable, substitution));
+                }
+                var resultVariable = body.getOrCreateVariableByName(leftJoinLiteral.getResultVariable().getUniqueName());
+                new LeftJoinConstraint(body, substitution, wrappedCall.pattern(), resultVariable, optionalColumn,
+                                leftJoinLiteral.getDefaultValue());
+        }
+
         private void translateRepresentativeElectionLiteral(RepresentativeElectionLiteral literal, PBody body) {
                 var substitution = translateSubstitution(literal.getArguments(), body);
                 var pattern = wrapConstraintWithIdentityArguments(literal.getTarget());
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/QueryWrapperFactory.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/QueryWrapperFactory.java
index a710dab3..f855f1f0 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/QueryWrapperFactory.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/QueryWrapperFactory.java
@@ -16,15 +16,15 @@ import tools.refinery.interpreter.matchers.psystem.queries.PQuery;
 import tools.refinery.interpreter.matchers.psystem.queries.PVisibility;
 import tools.refinery.interpreter.matchers.tuple.Tuple;
 import tools.refinery.interpreter.matchers.tuple.Tuples;
-import tools.refinery.store.query.Constraint;
-import tools.refinery.store.query.dnf.Dnf;
-import tools.refinery.store.query.dnf.DnfUtils;
-import tools.refinery.store.query.literal.AbstractCallLiteral;
-import tools.refinery.store.query.term.ParameterDirection;
-import tools.refinery.store.query.term.Variable;
+import tools.refinery.logic.Constraint;
+import tools.refinery.logic.dnf.Dnf;
+import tools.refinery.logic.dnf.DnfUtils;
+import tools.refinery.logic.literal.AbstractCallLiteral;
+import tools.refinery.logic.term.ParameterDirection;
+import tools.refinery.logic.term.Variable;
 import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.SymbolView;
-import tools.refinery.store.util.CycleDetectingMapper;
+import tools.refinery.logic.util.CycleDetectingMapper;
 
 import java.util.*;
 import java.util.function.ToIntFunction;
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatefulMultisetAggregator.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatefulMultisetAggregator.java
index 7552117b..936b3513 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatefulMultisetAggregator.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatefulMultisetAggregator.java
@@ -6,8 +6,8 @@
 package tools.refinery.store.query.interpreter.internal.pquery;
 
 import tools.refinery.interpreter.matchers.psystem.aggregations.IMultisetAggregationOperator;
-import tools.refinery.store.query.term.StatefulAggregate;
-import tools.refinery.store.query.term.StatefulAggregator;
+import tools.refinery.logic.term.StatefulAggregate;
+import tools.refinery.logic.term.StatefulAggregator;
 
 import java.util.stream.Stream;
 
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatelessMultisetAggregator.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatelessMultisetAggregator.java
index 2da7ba87..01432a5b 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatelessMultisetAggregator.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/StatelessMultisetAggregator.java
@@ -6,7 +6,7 @@
 package tools.refinery.store.query.interpreter.internal.pquery;
 
 import tools.refinery.interpreter.matchers.psystem.aggregations.IMultisetAggregationOperator;
-import tools.refinery.store.query.term.StatelessAggregator;
+import tools.refinery.logic.term.StatelessAggregator;
 
 import java.util.stream.Stream;
 
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/TermEvaluator.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/TermEvaluator.java
index ed991091..8da9ece7 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/TermEvaluator.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/TermEvaluator.java
@@ -5,8 +5,8 @@
  */
 package tools.refinery.store.query.interpreter.internal.pquery;
 
-import tools.refinery.store.query.term.Term;
-import tools.refinery.store.query.term.Variable;
+import tools.refinery.logic.term.Term;
+import tools.refinery.logic.term.Variable;
 import tools.refinery.interpreter.matchers.psystem.IExpressionEvaluator;
 import tools.refinery.interpreter.matchers.psystem.IValueProvider;
 
diff --git a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/ValueProviderBasedValuation.java b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/ValueProviderBasedValuation.java
index 4124c9bb..a69c8bd2 100644
--- a/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/ValueProviderBasedValuation.java
+++ b/subprojects/store-query-interpreter/src/main/java/tools/refinery/store/query/interpreter/internal/pquery/ValueProviderBasedValuation.java
@@ -6,8 +6,8 @@
 package tools.refinery.store.query.interpreter.internal.pquery;
 
 import tools.refinery.interpreter.matchers.psystem.IValueProvider;
-import tools.refinery.store.query.term.DataVariable;
-import tools.refinery.store.query.valuation.Valuation;
+import tools.refinery.logic.term.DataVariable;
+import tools.refinery.logic.valuation.Valuation;
 
 public record ValueProviderBasedValuation(IValueProvider valueProvider) implements Valuation {
         @Override
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/AggregatorBatchingTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/AggregatorBatchingTest.java
index d8e06d82..209d7ac0 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/AggregatorBatchingTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/AggregatorBatchingTest.java
@@ -9,10 +9,10 @@ import org.junit.jupiter.api.Test;
 import tools.refinery.store.model.Model;
 import tools.refinery.store.model.ModelStore;
 import tools.refinery.store.query.ModelQueryAdapter;
-import tools.refinery.store.query.dnf.Query;
-import tools.refinery.store.query.term.StatefulAggregate;
-import tools.refinery.store.query.term.StatefulAggregator;
-import tools.refinery.store.query.term.Variable;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.term.StatefulAggregate;
+import tools.refinery.logic.term.StatefulAggregator;
+import tools.refinery.logic.term.Variable;
 import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.FunctionView;
 import tools.refinery.store.query.view.KeyOnlyView;
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/DiagonalQueryTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/DiagonalQueryTest.java
index 76de8679..eba7173b 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/DiagonalQueryTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/DiagonalQueryTest.java
@@ -8,8 +8,8 @@ package tools.refinery.store.query.interpreter;
 import tools.refinery.interpreter.matchers.backend.QueryEvaluationHint;
 import tools.refinery.store.model.ModelStore;
 import tools.refinery.store.query.ModelQueryAdapter;
-import tools.refinery.store.query.dnf.Dnf;
-import tools.refinery.store.query.dnf.Query;
+import tools.refinery.logic.dnf.Dnf;
+import tools.refinery.logic.dnf.Query;
 import tools.refinery.store.query.interpreter.tests.QueryEngineTest;
 import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.FunctionView;
@@ -21,8 +21,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
-import static tools.refinery.store.query.literal.Literals.not;
-import static tools.refinery.store.query.term.int_.IntTerms.INT_SUM;
+import static tools.refinery.logic.literal.Literals.not;
+import static tools.refinery.logic.term.int_.IntTerms.INT_SUM;
 import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertNullableResults;
 import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertResults;
 
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/FunctionalQueryTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/FunctionalQueryTest.java
index b6c96676..c845e5ff 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/FunctionalQueryTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/FunctionalQueryTest.java
@@ -9,15 +9,15 @@ import tools.refinery.interpreter.matchers.backend.QueryEvaluationHint;
 import tools.refinery.store.map.Cursor;
 import tools.refinery.store.model.ModelStore;
 import tools.refinery.store.query.ModelQueryAdapter;
-import tools.refinery.store.query.dnf.Query;
-import tools.refinery.store.query.term.Variable;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.term.Variable;
 import tools.refinery.store.query.interpreter.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;
 import tools.refinery.store.representation.Symbol;
-import tools.refinery.store.representation.TruthValue;
+import tools.refinery.logic.term.truthvalue.TruthValue;
 import tools.refinery.store.tuple.Tuple;
 
 import java.util.List;
@@ -29,8 +29,8 @@ import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.nullValue;
 import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static tools.refinery.store.query.literal.Literals.check;
-import static tools.refinery.store.query.term.int_.IntTerms.*;
+import static tools.refinery.logic.literal.Literals.check;
+import static tools.refinery.logic.term.int_.IntTerms.*;
 import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertNullableResults;
 import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertResults;
 
@@ -554,7 +554,6 @@ class FunctionalQueryTest {
                 friendInterpretation.put(Tuple.of(1, 2), TruthValue.TRUE);
 
                 queryEngine.flushChanges();
-                queryEngine.flushChanges();
                 assertNullableResults(Map.of(
                                 Tuple.of(0), Optional.of(25),
                                 Tuple.of(1), Optional.of(32),
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/LeftJoinTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/LeftJoinTest.java
new file mode 100644
index 00000000..6633b3b1
--- /dev/null
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/LeftJoinTest.java
@@ -0,0 +1,129 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package tools.refinery.store.query.interpreter;
+
+import org.junit.jupiter.api.Test;
+import tools.refinery.store.model.ModelStore;
+import tools.refinery.store.query.ModelQueryAdapter;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.term.int_.IntTerms;
+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;
+import tools.refinery.store.tuple.Tuple;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertNullableResults;
+import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertResults;
+
+class LeftJoinTest {
+        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 FunctionView<Integer> ageView = new FunctionView<>(age);
+
+        @Test
+        void unarySymbolTest() {
+                var query = Query.of("Query", Integer.class, (builder, p1, output) -> builder
+                                .clause(
+                                                personView.call(p1),
+                                                output.assign(ageView.leftJoin(18, p1))
+                                ));
+
+                var store = ModelStore.builder()
+                                .symbols(person, age)
+                                .with(QueryInterpreterAdapter.builder()
+                                                .queries(query))
+                                .build();
+
+                var model = store.createEmptyModel();
+                var personInterpretation = model.getInterpretation(person);
+                var ageInterpretation = model.getInterpretation(age);
+                var queryEngine = model.getAdapter(ModelQueryAdapter.class);
+                var queryResultSet = queryEngine.getResultSet(query);
+
+                personInterpretation.put(Tuple.of(0), true);
+                personInterpretation.put(Tuple.of(1), true);
+                personInterpretation.put(Tuple.of(2), true);
+
+                ageInterpretation.put(Tuple.of(2), 24);
+
+                queryEngine.flushChanges();
+                assertNullableResults(Map.of(
+                                Tuple.of(0), Optional.of(18),
+                                Tuple.of(1), Optional.of(18),
+                                Tuple.of(2), Optional.of(24),
+                                Tuple.of(3), Optional.empty()
+                ), queryResultSet);
+
+                personInterpretation.put(Tuple.of(0), false);
+
+                ageInterpretation.put(Tuple.of(1), 20);
+                ageInterpretation.put(Tuple.of(2), null);
+
+                queryEngine.flushChanges();
+                assertNullableResults(Map.of(
+                                Tuple.of(0), Optional.empty(),
+                                Tuple.of(1), Optional.of(20),
+                                Tuple.of(2), Optional.of(18),
+                                Tuple.of(3), Optional.empty()
+                ), queryResultSet);
+        }
+
+        @Test
+        void unarySymbolWithAssignmentTest() {
+                // Tests an edge case where the outer joined variable is already bound in the query plan.
+                var query = Query.of("Query", (builder, p1) -> builder
+                                .clause(Integer.class, v1 -> List.of(
+                                                personView.call(p1),
+                                                v1.assign(IntTerms.constant(18)),
+                                                v1.assign(ageView.leftJoin(18, p1))
+                                )));
+
+                var store = ModelStore.builder()
+                                .symbols(person, age)
+                                .with(QueryInterpreterAdapter.builder()
+                                                .queries(query))
+                                .build();
+
+                var model = store.createEmptyModel();
+                var personInterpretation = model.getInterpretation(person);
+                var ageInterpretation = model.getInterpretation(age);
+                var queryEngine = model.getAdapter(ModelQueryAdapter.class);
+                var queryResultSet = queryEngine.getResultSet(query);
+
+                personInterpretation.put(Tuple.of(0), true);
+                personInterpretation.put(Tuple.of(1), true);
+                personInterpretation.put(Tuple.of(2), true);
+
+                ageInterpretation.put(Tuple.of(2), 24);
+
+                queryEngine.flushChanges();
+                assertResults(Map.of(
+                                Tuple.of(0), true,
+                                Tuple.of(1), true,
+                                Tuple.of(2), false,
+                                Tuple.of(3), false
+                ), queryResultSet);
+
+                personInterpretation.put(Tuple.of(0), false);
+
+                ageInterpretation.put(Tuple.of(1), 20);
+                ageInterpretation.put(Tuple.of(2), null);
+
+                queryEngine.flushChanges();
+                assertResults(Map.of(
+                                Tuple.of(0), false,
+                                Tuple.of(1), false,
+                                Tuple.of(2), true,
+                                Tuple.of(3), false
+                ), queryResultSet);
+        }
+}
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/OrderedResultSetTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/OrderedResultSetTest.java
index 96d0f302..cc3ddc10 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/OrderedResultSetTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/OrderedResultSetTest.java
@@ -8,9 +8,9 @@ package tools.refinery.store.query.interpreter;
 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.logic.dnf.Query;
 import tools.refinery.store.query.resultset.OrderedResultSet;
-import tools.refinery.store.query.term.Variable;
+import tools.refinery.logic.term.Variable;
 import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.KeyOnlyView;
 import tools.refinery.store.representation.Symbol;
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTest.java
index 72728dcd..59f43147 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTest.java
@@ -9,26 +9,26 @@ import tools.refinery.interpreter.matchers.backend.QueryEvaluationHint;
 import org.junit.jupiter.api.Test;
 import tools.refinery.store.model.ModelStore;
 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.term.ParameterDirection;
-import tools.refinery.store.query.term.Variable;
+import tools.refinery.logic.dnf.Dnf;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.term.ParameterDirection;
+import tools.refinery.logic.term.Variable;
 import tools.refinery.store.query.interpreter.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;
 import tools.refinery.store.representation.Symbol;
-import tools.refinery.store.representation.TruthValue;
+import tools.refinery.logic.term.truthvalue.TruthValue;
 import tools.refinery.store.tuple.Tuple;
 
 import java.util.List;
 import java.util.Map;
 
-import static tools.refinery.store.query.literal.Literals.check;
-import static tools.refinery.store.query.literal.Literals.not;
-import static tools.refinery.store.query.term.int_.IntTerms.constant;
-import static tools.refinery.store.query.term.int_.IntTerms.greaterEq;
+import static tools.refinery.logic.literal.Literals.check;
+import static tools.refinery.logic.literal.Literals.not;
+import static tools.refinery.logic.term.int_.IntTerms.constant;
+import static tools.refinery.logic.term.int_.IntTerms.greaterEq;
 import static tools.refinery.store.query.interpreter.tests.QueryAssertions.assertResults;
 
 class QueryTest {
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTransactionTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTransactionTest.java
index 1cd05d91..eb1ed68a 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTransactionTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/QueryTransactionTest.java
@@ -9,8 +9,8 @@ import tools.refinery.interpreter.matchers.backend.QueryEvaluationHint;
 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.logic.dnf.Query;
+import tools.refinery.logic.dnf.RelationalQuery;
 import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.FilteredView;
 import tools.refinery.store.query.view.FunctionView;
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/StronglyConnectedComponentsTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/StronglyConnectedComponentsTest.java
index edbd9aff..f8b12d19 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/StronglyConnectedComponentsTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/StronglyConnectedComponentsTest.java
@@ -6,11 +6,11 @@
 package tools.refinery.store.query.interpreter;
 
 import org.junit.jupiter.api.Test;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.literal.Connectivity;
+import tools.refinery.logic.literal.RepresentativeElectionLiteral;
 import tools.refinery.store.model.ModelStore;
 import tools.refinery.store.query.ModelQueryAdapter;
-import tools.refinery.store.query.dnf.Query;
-import tools.refinery.store.query.literal.Connectivity;
-import tools.refinery.store.query.literal.RepresentativeElectionLiteral;
 import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.KeyOnlyView;
 import tools.refinery.store.representation.Symbol;
diff --git a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/WeaklyConnectedComponentsTest.java b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/WeaklyConnectedComponentsTest.java
index 3fc85480..95b37f09 100644
--- a/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/WeaklyConnectedComponentsTest.java
+++ b/subprojects/store-query-interpreter/src/test/java/tools/refinery/store/query/interpreter/WeaklyConnectedComponentsTest.java
@@ -6,11 +6,11 @@
 package tools.refinery.store.query.interpreter;
 
 import org.junit.jupiter.api.Test;
+import tools.refinery.logic.dnf.Query;
+import tools.refinery.logic.literal.Connectivity;
+import tools.refinery.logic.literal.RepresentativeElectionLiteral;
 import tools.refinery.store.model.ModelStore;
 import tools.refinery.store.query.ModelQueryAdapter;
-import tools.refinery.store.query.dnf.Query;
-import tools.refinery.store.query.literal.Connectivity;
-import tools.refinery.store.query.literal.RepresentativeElectionLiteral;
 import tools.refinery.store.query.view.AnySymbolView;
 import tools.refinery.store.query.view.KeyOnlyView;
 import tools.refinery.store.representation.Symbol;