diff --git a/src/main/java/inference/rewrite/RewriteInferenceSystem.java b/src/main/java/inference/rewrite/RewriteInferenceSystem.java
index 15643a0..0f214b0 100644
--- a/src/main/java/inference/rewrite/RewriteInferenceSystem.java
+++ b/src/main/java/inference/rewrite/RewriteInferenceSystem.java
@@ -79,8 +79,10 @@
 			System.out.println("Loop is detected");
 			return false;
 		}
+		Set<ResourceTree> conclusionLeftResult = new HashSet<>();
+		Set<ResourceTree> conclusionRightResult = new HashSet<>();
 		for (EquationFormula inputFormula : inputFormulas) {
-			System.out.println("---------------------------" + inputFormula + "-------------------------------------------------");
+//			System.out.println("---------------------------" + inputFormula + "-------------------------------------------------");
 //			ResourceTree baseTree = expandTree(i);
 //			System.out.println("baseTree: " + baseTree);
 //			Set<ResourceTree> result = rewriteTree(baseTree, i);
@@ -96,12 +98,9 @@
 //			System.out.println("=====================================");
 			Map<ResourceTree, Set<RewriteGraphNode>> leftRewriteGraph = new HashMap<>();
 			Map<ResourceTree, Set<RewriteGraphNode>> rightRewriteGraph = new HashMap<>();
-			Set<ResourceTree> conclusionLeftResult = rewriteTree(new ResourceTree(conclusion.getLeftSideHand()), inputFormula, leftRewriteGraph);
-			Set<ResourceTree> conclusionRightResult = rewriteTree(new ResourceTree(conclusion.getRightSideHand()), inputFormula, rightRewriteGraph);
-//			System.out.println(conclusionLeftResult);
+			conclusionLeftResult.addAll(rewriteTree(new ResourceTree(conclusion.getLeftSideHand()), inputFormula, leftRewriteGraph));
+			conclusionRightResult.addAll(rewriteTree(new ResourceTree(conclusion.getRightSideHand()), inputFormula, rightRewriteGraph));
 //			System.out.println(conclusionRightResult);
-			conclusionLeftResult.retainAll(conclusionRightResult);
-			System.out.println(conclusionLeftResult.size() != 0);
 //			if (conclusionLeftResult.size() != 0) {
 //				ResourceTree resultRoot = conclusionLeftResult.iterator().next();
 //				showRewriteGraph(resultRoot, leftRewriteGraph);
@@ -111,8 +110,9 @@
 //			}
 			
 		}	
-		
-		return false;
+		conclusionLeftResult.retainAll(conclusionRightResult);
+//		System.out.println(conclusionLeftResult.size() != 0);
+		return conclusionLeftResult.size() != 0;
 	}
 	
 	
diff --git a/src/test/java/rewrite/RewriteInferenceTest.java b/src/test/java/rewrite/RewriteInferenceTest.java
new file mode 100644
index 0000000..d9d445b
--- /dev/null
+++ b/src/test/java/rewrite/RewriteInferenceTest.java
@@ -0,0 +1,107 @@
+package rewrite;
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import inference.rewrite.RewriteInferenceSystem;
+import models.formulas.EquationFormula;
+import models.formulas.Then;
+import models.terms.DependencyTerm;
+import models.terms.PrimedTerm;
+import models.terms.Resource;
+import utils.Utils;
+
+public class RewriteInferenceTest {
+
+	@Test
+	void RewriteInferenceTest1() {
+		Resource totalAmount = new Resource("totalAmount", Utils.INT, 1);
+		Resource quantity = new Resource("quantity", Utils.INT, 1);
+		Resource unitPrice = new Resource("unitPrice", Utils.INT, 1);
+		Resource productId = new Resource("productID", Utils.INT, 1);
+		Resource productName = new Resource("productName", Utils.INT, 1);
+		Resource soledProductId = new Resource("soledProductId", Utils.INT, 1);
+		PrimedTerm totalAmountP = new PrimedTerm(totalAmount);
+		PrimedTerm quantityP = new PrimedTerm(quantity);
+		PrimedTerm unitPriceP = new PrimedTerm(unitPrice);
+		PrimedTerm productIdP = new PrimedTerm(productId);
+		PrimedTerm productNameP = new PrimedTerm(productName);
+		PrimedTerm soledProductIdP = new PrimedTerm(soledProductId);
+		Resource a = new Resource("a", Utils.INT, 0);
+		Resource b = new Resource("b", Utils.INT, 0);
+		Resource c = new Resource("c", Utils.INT, 0);
+		Resource d = new Resource("d", Utils.INT, 0);
+		Resource e = new Resource("e", Utils.INT, 0);
+		Resource salesId = new Resource("salesId", Utils.INT, 1);
+		PrimedTerm salesIdP = new PrimedTerm(salesId);
+		Resource mul = new Resource("mul", Utils.INT, 1);
+		Resource mul1= new Resource("mul1", Utils.INT, 1);
+		Resource mul2 = new Resource("mul2", Utils.INT, 1);
+		
+		// reference1
+		DependencyTerm te1 = new DependencyTerm(unitPrice, productId, soledProductId);
+		DependencyTerm te2 = new DependencyTerm(mul, mul1, quantity, mul2, te1);
+		EquationFormula eq1 = new EquationFormula(totalAmount, te2);
+		
+		//reference2
+		DependencyTerm te3 = new DependencyTerm(unitPriceP, productIdP, soledProductIdP);
+		DependencyTerm te4 = new DependencyTerm(mul, mul1, quantityP, mul2, te3);
+		EquationFormula eq2 = new EquationFormula(totalAmountP, te4);
+		
+		//input1
+		DependencyTerm te5 = new DependencyTerm(soledProductIdP, salesIdP, a);
+		EquationFormula eq3 = new EquationFormula(te5, b);
+		
+		//input2
+		DependencyTerm te6 = new DependencyTerm(quantityP, salesIdP, a);
+		EquationFormula eq4 = new EquationFormula(te6, c);
+		
+		//input3, 4, 5
+		EquationFormula eq5 = new EquationFormula(productIdP, productId);
+		EquationFormula eq6 = new EquationFormula(productNameP, productName);
+		EquationFormula eq7 = new EquationFormula(unitPriceP, unitPrice);
+		
+		// value copy
+		DependencyTerm te7 = new DependencyTerm(totalAmountP, salesIdP, a);
+		DependencyTerm te8 = new DependencyTerm(unitPriceP, productIdP, b);
+		DependencyTerm te9 = new DependencyTerm(mul, mul1, c, mul2, te8);
+		EquationFormula eq8 = new EquationFormula(te7, te9);
+		
+		
+		//----------------------change value-------------------
+		//input6
+		DependencyTerm te10 = new DependencyTerm(unitPriceP, productIdP, d);
+		EquationFormula eq9 = new EquationFormula(te10, e);
+		
+		//input7, 8, 9, 10
+		EquationFormula eq10 = new EquationFormula(productNameP, productName);
+		EquationFormula eq11 = new EquationFormula(salesIdP, salesId);
+		EquationFormula eq12 = new EquationFormula(soledProductIdP, soledProductId);
+		EquationFormula eq13 = new EquationFormula(quantityP, quantity);
+		
+		//value copy
+		EquationFormula eq14 = new EquationFormula(totalAmountP, totalAmount);
+		
+		//value copy conclusion
+		DependencyTerm te11 = new DependencyTerm(totalAmountP, salesIdP, a);
+		DependencyTerm te12 = new DependencyTerm(totalAmount, salesId, a);
+		EquationFormula eq15 = new EquationFormula(te11, te12);
+		
+		//value copy change value
+		RewriteInferenceSystem ris = new RewriteInferenceSystem(List.of(eq9, eq10, eq11, eq12, eq13, eq14), eq15);
+		assertTrue(ris.inference());
+		
+		//reference conclusion
+		DependencyTerm te13 = new DependencyTerm(soledProductId, salesId, a);
+		EquationFormula eq16 = new EquationFormula(d, te13);
+		Then th1 = new Then(eq16, eq15);
+		
+		//reference change value
+		RewriteInferenceSystem ris2 = new RewriteInferenceSystem(List.of(eq1, eq2, eq9, eq10, eq11, eq12, eq13), th1);
+		
+		assertFalse(ris2.inference());
+	}
+	
+}