1 files changed, 25 insertions, 22 deletions

diff --git a/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java b/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java
index 9486dc2a..a9efc4bb 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java
+++ b/subprojects/language/src/main/java/tools/refinery/language/utils/ProblemUtil.java
@@ -7,33 +7,12 @@ package tools.refinery.language.utils;
 
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EObject;
-
-import tools.refinery.language.model.problem.ImplicitVariable;
-import tools.refinery.language.model.problem.Node;
-import tools.refinery.language.model.problem.ProblemPackage;
-import tools.refinery.language.model.problem.Variable;
+import tools.refinery.language.model.problem.*;
 
 public final class ProblemUtil {
         public static final String BUILTIN_LIBRARY_NAME = "builtin";
-
         public static final URI BUILTIN_LIBRARY_URI = getLibraryUri(BUILTIN_LIBRARY_NAME);
 
-        public static final String NODE_CLASS_NAME = "node";
-
-        public static final String DOMAIN_CLASS_NAME = "domain";
-
-        public static final String DATA_CLASS_NAME = "data";
-
-        public static final String INT_CLASS_NAME = "int";
-
-        public static final String REAL_CLASS_NAME = "real";
-
-        public static final String STRING_CLASS_NAME = "string";
-
-        public static final String EQUALS_RELATION_NAME = "equals";
-
-        public static final String EXISTS_PREDICATE_NAME = "exists";
-
         private ProblemUtil() {
                 throw new IllegalStateException("This is a static utility class and should not be instantiated directly");
         }
@@ -70,6 +49,10 @@ public final class ProblemUtil {
                 }
         }
 
+        public static boolean isError(EObject eObject) {
+                return eObject instanceof PredicateDefinition predicateDefinition && predicateDefinition.isError();
+        }
+
         public static boolean isIndividualNode(Node node) {
                 var containingFeature = node.eContainingFeature();
                 return containingFeature == ProblemPackage.Literals.INDIVIDUAL_DECLARATION__NODES
@@ -80,6 +63,26 @@ public final class ProblemUtil {
                 return node.eContainingFeature() == ProblemPackage.Literals.CLASS_DECLARATION__NEW_NODE;
         }
 
+        public static boolean isInvalidMultiplicityConstraint(PredicateDefinition predicateDefinition) {
+                return predicateDefinition.eContainingFeature() ==
+                                ProblemPackage.Literals.REFERENCE_DECLARATION__INVALID_MULTIPLICITY;
+        }
+
+        public static boolean hasMultiplicityConstraint(ReferenceDeclaration referenceDeclaration) {
+                var opposite = referenceDeclaration.getOpposite();
+                if (opposite != null && opposite.getKind() == ReferenceKind.CONTAINMENT) {
+                        return false;
+                }
+                var multiplicity = referenceDeclaration.getMultiplicity();
+                if (multiplicity instanceof UnboundedMultiplicity) {
+                        return false;
+                }
+                if (multiplicity instanceof RangeMultiplicity rangeMultiplicity) {
+                        return rangeMultiplicity.getLowerBound() > 0 || rangeMultiplicity.getUpperBound() >= 0;
+                }
+                return true;
+        }
+
         private static URI getLibraryUri(String libraryName) {
                 return URI.createURI(ProblemUtil.class.getClassLoader()
                                 .getResource("tools/refinery/language/%s.problem".formatted(libraryName)).toString());