diff --git a/sources/zweic/Parser.scala b/sources/zweic/Parser.scala
index 1e8223d..2dc61b0 100755
--- a/sources/zweic/Parser.scala
+++ b/sources/zweic/Parser.scala
@@ -296,62 +296,67 @@
 
   /**
   * CmpExpression = [ SumExpression CompOp ] SumExpression
-  * MyCmpExpression = SumExpression [ CompOp SumExpression ]
+  * MyCmpExpression = SumExpression { CompOp SumExpression }
   */
   private def cmpExpression(): Expr = {
-	val left = sumExpression();
-	if ( token == EQ || token == NE || token == LT
+	var left = sumExpression();
+	while ( token == EQ || token == NE || token == LT
 	|| token == GT || token == LE || token == GE ) {
-		val op = compOp();
-		val right = sumExpression();
-		return Binop(op, left, right);
+		var op = compOp();
+		var right = sumExpression();
+		left = Binop(op, left, right);
 	}
 	return left;
   }
 
   /**
   * SumExpression = Term | SumExpression SumOp Term
-  * MySumExpression = Term [ SumOp SumExpression ]
+  * MySumExpression = Term { SumOp Term }
   */
   private def sumExpression(): Expr = {
-	val left = term();
-	if ( token == ADD || token == SUB ) {
-		return Binop(sumOp(), left, sumExpression());
-	} else {
-		if (check(OR)) {	
-		  var right = sumExpression();
-		  left.brackets = true;
-		  right.brackets = true;
-		  var bo = Binop(Operators.AND, Unop(Operators.NOT, left), Unop(Operators.NOT, right));
-		  bo.brackets = true;
-		  return Unop(Operators.NOT, bo);
+	var left = term();
+
+	while ( token == ADD || token == SUB || token == OR ) {
+		if ( check(OR) ) {
+			var right = term();
+			left.brackets = true;
+			right.brackets = true;
+			var bo = Binop(Operators.AND, Unop(Operators.NOT, left), Unop(Operators.NOT, right));
+			bo.brackets = true;
+			left = Unop(Operators.NOT, bo);
 		} else {
-			return left;
+			left = Binop(sumOp(), left, term());
 		}
 	}
+
+	return left;
   }
 
   /**
   * Term = [ Term ProdOp ] [ NegateOp ] Factor
-  * MyTerm = [ NegateOp ] Factor [ ProdOp Term ]
+  * MyTerm = [ NegateOp ] Factor { ProdOp [ NegateOp ] Factor }
   */
   private def term(): Expr = {
-	var left:Expr = null;	
+	var left:Expr = _negFactor();
+
+	while ( token == MUL || token == DIV || token == MOD || token == AND ) {
+		var op = prodOp();
+		left = Binop(op, left, _negFactor());
+	}
+
+	return left;
+  }
+
+  private def _negFactor(): Expr =
 	if ( token == SUB || token == NOT ) {
 		val op = Operators.token2op(token);
 		nextToken;
 		val e = factor();
-		left = Unop(op, e);
+		e.brackets = true;
+		return Unop(op, e);
 	} else {
-		left = factor();
+		return factor();
 	}
-	if ( token == MUL || token == DIV || token == MOD || token == AND ) {
-		val op = prodOp();
-		val right = term();
-		return Binop(op, left, right);
-	}
-	return left;
-  }
 
   private def _string(str: String): New = {
   	// TODO: make this less dirty