1 files changed, 15 insertions, 14 deletions

diff --git a/subprojects/store/src/main/java/tools/refinery/store/representation/TruthValueDomain.java b/subprojects/store/src/main/java/tools/refinery/store/representation/TruthValueDomain.java
index 89f8dd19..61696dca 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/representation/TruthValueDomain.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/representation/TruthValueDomain.java
@@ -7,6 +7,8 @@ package tools.refinery.store.representation;
 
 import java.util.Optional;
 
+// Singleton pattern, because there is only one domain for truth values.
+@SuppressWarnings("squid:S6548")
 public final class TruthValueDomain implements AbstractDomain<TruthValue, Boolean> {
         public static final TruthValueDomain INSTANCE = new TruthValueDomain();
 
@@ -15,51 +17,50 @@ public final class TruthValueDomain implements AbstractDomain<TruthValue, Boolea
 
         @Override
         public Class<TruthValue> abstractType() {
-                return null;
+                return TruthValue.class;
         }
 
         @Override
         public Class<Boolean> concreteType() {
-                return null;
+                return Boolean.class;
         }
 
         @Override
         public TruthValue toAbstract(Boolean concreteValue) {
-                return null;
+                return TruthValue.toTruthValue(concreteValue);
         }
 
         @Override
         public Optional<Boolean> toConcrete(TruthValue abstractValue) {
-                return Optional.empty();
+                return switch (abstractValue) {
+                        case TRUE -> Optional.of(true);
+                        case FALSE -> Optional.of(false);
+                        default -> Optional.empty();
+                };
         }
 
         @Override
         public boolean isConcrete(TruthValue abstractValue) {
-                return AbstractDomain.super.isConcrete(abstractValue);
-        }
-
-        @Override
-        public boolean isRefinement(TruthValue originalValue, TruthValue refinedValue) {
-                return false;
+                return abstractValue.isConcrete();
         }
 
         @Override
         public TruthValue commonRefinement(TruthValue leftValue, TruthValue rightValue) {
-                return null;
+                return leftValue.merge(rightValue);
         }
 
         @Override
         public TruthValue commonAncestor(TruthValue leftValue, TruthValue rightValue) {
-                return null;
+                return leftValue.join(rightValue);
         }
 
         @Override
         public TruthValue unknown() {
-                return null;
+                return TruthValue.UNKNOWN;
         }
 
         @Override
         public boolean isError(TruthValue abstractValue) {
-                return false;
+                return !abstractValue.isConsistent();
         }
 }