diff --git a/src/main/java/Main.java b/src/main/java/Main.java
index 1058c2e..fbf1310 100644
--- a/src/main/java/Main.java
+++ b/src/main/java/Main.java
@@ -139,6 +139,27 @@
 		
 	}
 	
+	static void sandbox6() {
+		Resource add = new Resource("add", INT, 1);
+		Resource cid = new Resource("cid", INT, 1);
+		Resource org = new Resource("org", INT, 1);
+		Resource uid = new Resource("uid", INT, 1);
+		Resource x = new Resource("x", INT, 0);
+		Resource y = new Resource("y", INT, 0);
+		Resource z = new Resource("z", INT, 0);
+		
+		DependencyTerm t1 = new DependencyTerm(add, cid, x);
+		DependencyTerm t2 = new DependencyTerm(cid, uid, z);
+		DependencyTerm t3 = new DependencyTerm(add, cid, t2);
+		EquationFormula f1 = new EquationFormula(t1, y);
+		EquationFormula f2 = new EquationFormula(t2, x);
+		EquationFormula f3 = new EquationFormula(t3, y);
+		Then f4 = new Then(f2, f3);
+		RewriteInferenceSystem ris = new RewriteInferenceSystem(List.of(f1), f4);
+		ris.inference();
+		
+	}
+	
 	
 	static void sandbox7() {
 		Resource A = new Resource("A",  INT, 1);