anchor.diff:      var joinName = newName('join');
       ast.FunctionExpression joinFun = reifyStatementCont(s);
       joinFun.parameters = AstFactory.formalParameterList(
  -        [AstFactory.simpleFormalParameter3('_')]);
  +        [AstFactory.simpleFormalParameter3(newName('x'))]);
       addStatement(
           AstFactory.functionDeclarationStatement(null, null, joinName, joinFun));
   
  
positive.code:     currentBlock = savedBlock;
      addStatement(
          AstFactory.functionDeclarationStatement(null, null, breakName,
              functionExpression(['_'], breakBlock)));
      addStatement(
          AstFactory.functionDeclarationStatement(null, null, loopName,
              functionExpression(parameters.map((e) => e.name).toList(),
  
negative.code:     currentBlock = savedBlock;
      addStatement(
          AstFactory.functionDeclarationStatement(null, null, breakName,
              functionExpression([newName('x')], breakBlock)));
      addStatement(
          AstFactory.functionDeclarationStatement(null, null, continueName,
              functionExpression([newName('x')], continueBlock)));
      addStatement(
          AstFactory.functionExpressionInvocation(
              identifier(continueName), [nullLiteral()]));
  