1 files changed, 15 insertions, 0 deletions

diff --git a/subprojects/store-query/src/main/java/tools/refinery/store/query/dnf/FunctionalDependency.java b/subprojects/store-query/src/main/java/tools/refinery/store/query/dnf/FunctionalDependency.java
new file mode 100644
index 00000000..f4cd109f
--- /dev/null
+++ b/subprojects/store-query/src/main/java/tools/refinery/store/query/dnf/FunctionalDependency.java
@@ -0,0 +1,15 @@
+package tools.refinery.store.query.dnf;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public record FunctionalDependency<T>(Set<T> forEach, Set<T> unique) {
+        public FunctionalDependency {
+                var uniqueForEach = new HashSet<>(unique);
+                uniqueForEach.retainAll(forEach);
+                if (!uniqueForEach.isEmpty()) {
+                        throw new IllegalArgumentException("Variables %s appear on both sides of the functional dependency"
+                                        .formatted(uniqueForEach));
+                }
+        }
+}