1 files changed, 55 insertions, 0 deletions

diff --git a/subprojects/logic/src/main/java/tools/refinery/logic/term/AnyDataVariable.java b/subprojects/logic/src/main/java/tools/refinery/logic/term/AnyDataVariable.java
new file mode 100644
index 00000000..3376bdc9
--- /dev/null
+++ b/subprojects/logic/src/main/java/tools/refinery/logic/term/AnyDataVariable.java
@@ -0,0 +1,55 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package tools.refinery.logic.term;
+
+import org.jetbrains.annotations.Nullable;
+import tools.refinery.logic.InvalidQueryException;
+import tools.refinery.logic.equality.LiteralEqualityHelper;
+
+import java.util.Optional;
+import java.util.Set;
+
+public abstract sealed class AnyDataVariable extends Variable implements AnyTerm permits DataVariable {
+        protected AnyDataVariable(String name) {
+                super(name);
+        }
+
+        @Override
+        public Optional<Class<?>> tryGetType() {
+                return Optional.of(getType());
+        }
+
+        @Override
+        public boolean isNodeVariable() {
+                return false;
+        }
+
+        @Override
+        public boolean isDataVariable() {
+                return true;
+        }
+
+        @Override
+        public NodeVariable asNodeVariable() {
+                throw new InvalidQueryException("%s is a data variable".formatted(this));
+        }
+
+        @Override
+        public boolean equalsWithSubstitution(LiteralEqualityHelper helper, AnyTerm other) {
+                return other instanceof AnyDataVariable dataVariable && helper.variableEqual(this, dataVariable);
+        }
+
+        @Override
+        public Set<AnyDataVariable> getInputVariables() {
+                return Set.of(this);
+        }
+
+        @Override
+        public abstract AnyDataVariable renew(@Nullable String name);
+
+        @Override
+        public abstract AnyDataVariable renew();
+}