Hello everybody. I have this question :
I need to create a paradict "rightGuesses" which will get 3 arguments , each one of them is a list of letters :
1) The list of guessed letters
2) The word i have to guess
3) The letters that where guessed so far .

for example :
rightGuesses([n,o,p,q], [p,r,o,l,o,g], Ans). will give us Ans = [p, -, o, -, o, -].

i made:
rightGuesses([],T2,[ANS])
rightGuesses([A|T1],T2,[ANS]):- (member(A,T2))=\=true , rightGuesses(T1,T2,[ _ |'-']).
rightGuesses([A|T1],T2,[ANS]):- member(A,T2), rightGuesses(T1,T2,[ _ |A]).

but i get :

ERROR: c:/users/leonid/desktop/file3.pl:5:0: Syntax error: Operator expected Warning: c:/users/leonid/desktop/file3.pl:6:

when i trying to compile it what is my problem , and is there is a better way to do it ?
thanks in advance.