End Google Ads 201810 - BS.net 01 --> hi every one, i'm trying to write a simple code in clips but I'm getting this error which i can't find what the problem is.
I would be grateful if any one could help.

Defining deffunction: user-Question
Defining defrule: Rule0
[PRNTUTIL2] Syntax Error: Check appropriate syntax for defrule.

ERROR:
(defrule MAIN::Rule0
(not (tank-is-full ?)
=>

this is part of my code:

Quote:
;;;************;;;* Functions*;;;************(deffunction user-Question(?question ?answer $?values) (printout t ?question) (bind ?answer(read)) (stringp ?answer) => (bind ?answer(lowcase ?answer)) (while (not (member$ ?answer ?values)) do (printout t ?question) (bind ?answer(read)) (stringp ?answer) => (bind ?answer(lowcase ?answer)) ) ?answer) ;;;**********************;;;* ENGINE STATE RULES *;;;********************** (defrule Rule0 (not (tank-is-full ?) => (bind ?tank-is-full user-Question("Is there any petrol in the tank(Yes|No)?"yes YES Yes NO no No) (assert(tank-is-full ?tank-is-full) );;;****************************