first test for isDerivable

src/main/java/edu/kit/formal/interpreter/KeYMatcher.java

@@ -118,12 +118,12 @@ public class KeYMatcher implements MatcherApi<KeyData> {
      * @param term
      * @return null if the term is not derivable or the new state
      */
-    public GoalNode<KeyData> isDerivable(Proof proof, GoalNode<KeyData> kd, Term term) {
+    public static GoalNode<KeyData> isDerivable(Proof proof, GoalNode<KeyData> kd, Term term) {
         Taclet cut = proof.getEnv().getInitConfigForEnvironment().lookupActiveTaclet(CUT_TACLET_NAME);
         TacletApp app = NoPosTacletApp.createNoPosTacletApp(cut);
         SchemaVariable sv = (SchemaVariable) app.uninstantiatedVars().iterator().next();
         TacletApp cutApp = app.addCheckedInstantiation(sv, term, proof.getServices(), true);
-        ImmutableList<Goal> goalList = kd.getData().getGoal().apply(app);
+        ImmutableList<Goal> goalList = kd.getData().getGoal().apply(cutApp);
 
         if(goalList.size() !=2) {
             throw new IllegalStateException("Cut created more than two sub goals!");

src/test/java/edu/kit/formal/interpreter/KeyMatcherDerivableTest.java

+package edu.kit.formal.interpreter;
+
+import de.uka.ilkd.key.logic.Term;
+import de.uka.ilkd.key.logic.TermBuilder;
+import de.uka.ilkd.key.proof.Goal;
+import de.uka.ilkd.key.proof.Proof;
+import edu.kit.formal.interpreter.data.GoalNode;
+import edu.kit.formal.interpreter.data.KeyData;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.File;
+
+/**
+ * Created by weigl on 15.07.2017.
+ */
+public class KeyMatcherDerivableTest {
+    @Test
+    public void derivable_test_1() throws Exception {
+        KeYProofFacade f = new KeYProofFacade();
+        f.loadKeyFile(new File("src/test/resources/edu/kit/formal/proofscriptparser/derivable_test_1.key"));
+        Proof proof = f.getProof();
+
+        Goal g = proof.getGoal(proof.root());
+        GoalNode<KeyData> gn = new GoalNode<>(null, new KeyData(g, f.getEnvironment(), proof));
+        Term termQ = new TermBuilder(f.getEnvironment().getServices().getTermFactory(),
+                f.getEnvironment().getServices()).parseTerm("q");
+        System.out.println(termQ);
+        GoalNode<KeyData> a = KeYMatcher.isDerivable(proof, gn, termQ);
+
+
+        System.out.println(proof);
+
+        Assert.assertNotNull(a);
+
+        Assert.assertEquals(1, proof.getSubtreeGoals(proof.root()).size());
+    }
+
+}
\ No newline at end of file

src/test/resources/edu/kit/formal/proofscriptparser/derivable_test_1.key

+\sorts {
+	s;
+}
+
+\predicates {
+	p;
+	q;
+}
+
+\problem {
+     !(p -> q) | !p
+}