1 files changed, 24 insertions, 1 deletions

diff --git a/subprojects/store/src/main/java/tools/refinery/store/representation/cardinality/FiniteUpperCardinality.java b/subprojects/store/src/main/java/tools/refinery/store/representation/cardinality/FiniteUpperCardinality.java
index 82afdbbc..b63a8637 100644
--- a/subprojects/store/src/main/java/tools/refinery/store/representation/cardinality/FiniteUpperCardinality.java
+++ b/subprojects/store/src/main/java/tools/refinery/store/representation/cardinality/FiniteUpperCardinality.java
@@ -6,6 +6,7 @@
 package tools.refinery.store.representation.cardinality;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.function.IntBinaryOperator;
 
@@ -22,6 +23,15 @@ public record FiniteUpperCardinality(int finiteUpperBound) implements UpperCardi
         }
 
         @Override
+        @Nullable
+        public UpperCardinality take(int count) {
+                if (finiteUpperBound < count) {
+                        return null;
+                }
+                return new FiniteUpperCardinality(finiteUpperBound - count);
+        }
+
+        @Override
         public UpperCardinality multiply(UpperCardinality other) {
                 return lift(other, (a, b) -> a * b);
         }
@@ -49,7 +59,7 @@ public record FiniteUpperCardinality(int finiteUpperBound) implements UpperCardi
 
         private UpperCardinality lift(@NotNull UpperCardinality other, IntBinaryOperator operator) {
                 if (other instanceof FiniteUpperCardinality finiteUpperCardinality) {
-                        return UpperCardinalities.valueOf(operator.applyAsInt(finiteUpperBound,
+                        return UpperCardinalities.atMost(operator.applyAsInt(finiteUpperBound,
                                         finiteUpperCardinality.finiteUpperBound));
                 }
                 if (other instanceof UnboundedUpperCardinality) {
@@ -57,4 +67,17 @@ public record FiniteUpperCardinality(int finiteUpperBound) implements UpperCardi
                 }
                 throw new IllegalArgumentException("Unknown UpperCardinality: " + other);
         }
+
+        @Override
+        public boolean equals(Object o) {
+                if (this == o) return true;
+                if (o == null || getClass() != o.getClass()) return false;
+                FiniteUpperCardinality that = (FiniteUpperCardinality) o;
+                return finiteUpperBound == that.finiteUpperBound;
+        }
+
+        @Override
+        public int hashCode() {
+                return finiteUpperBound;
+        }
 }