Another Question (write does not appear)

[Tenes]

Hello,

I just want to know If it's a way to print the Ok.
I cant understand why it doesnt show up.
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testpass(test,test,blue,ten,zer,ben).

start:- write('username:'),
read(A),nl,

write('password :'),
read(B),nl,
number(0).

number(0):-
writeln('Favourite colour:'),
read(C),
testpass(Dbusername,Dbpassword,Colour,_,_,_),
A==Dbusername,
B==Dbpassword,
C==Colour,
write('Ok').
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1 ?- start.
username:test.

password :test.

true.
-----------------------------------------------------------
Thanks

 

[joel76]

A is not bound, neither B in number(0), so A == Dbusername fails.