fix compiler error

lang/src/main/java/edu/kit/iti/formal/psdbg/parser/ASTTraversal.java

@@ -194,4 +194,10 @@ public interface ASTTraversal<T> extends Visitor<T> {
         defCase.getBody().accept(this);
         return null;
     }
+
+    @Override
+    default T visit(FunctionCall func) {
+        func.getArguments().forEach(a -> a.accept(this));
+        return null;
+    }
 }

rt/src/main/java/edu/kit/iti/formal/psdbg/interpreter/dbg/StateWrapper.java

@@ -124,7 +124,7 @@ public class StateWrapper<T> implements InterpreterObserver<T> {
 
         @Override
         public Void defaultVisit(ASTNode node) {
-            LOGGER.error("enter {}", node.accept(new ShortCommandPrinter()));
+            LOGGER.debug("enter {}", node.accept(new ShortCommandPrinter()));
             createNormalNode(node);
             return null;
         }
@@ -136,7 +136,7 @@ public class StateWrapper<T> implements InterpreterObserver<T> {
 
         @Override
         public Void visit(ProofScript proofScript) {
-            LOGGER.error("enter {}", proofScript.accept(new ShortCommandPrinter()));
+            LOGGER.debug("enter {}", proofScript.accept(new ShortCommandPrinter()));
             if (root) {
                 createRoot(proofScript);
                 root = false;