anchor.diff:  						console.log('stack : '+ JSON.stringify(stack));
   						throw new Error("Error formula is illegal : " + formula + ' : param_s : ' + JSON.stringify(param_s));
   					}
  -
  -					return stack[0];
  +					var rtn = stack[0];
  +					if( ! $.isNumeric(rtn) ){
  +						throw new Error("Error var " + rtn + ' is not resolved ');
  +					}
  +
  +					return rtn;
   				}
   
   				function if_nullOrUndef_then_return_init(param, init){
  
positive.code: 								}else{
  									throw new TypeError('func if param bool is required.');
  								}
  								func_name = param_s.shift();
  								this[func_name].apply(this, param_s);
  								return this;
  							}
  					};
  
negative.code: 					}
  				}
  
  				console.log(reverse_porlish_notation('$0 $1 +', {"$0":1,"$1":3}) === 4);
  				console.log(reverse_porlish_notation('4 (6 (3 $0 +) +) * 2 (1 $1 +) * /', {"$0":1,"$1":3}) === 5);
  
  				console.log(reverse_porlish_notation('1 5 + 2 3 + *') === 30);
  