built predicate into prolog

Question

input = *
value = 3
output = ***(3 star）

use prolog to write out the coding when key in value is 3 than the output is ***（3star) or when key in value is 5 than output is *****(5 star).

so i want to ask what are the coding in prolog for this question.

my answer is like below but cannot compile and have error. can check for me??

start:-
     write('input:'),
     read(X),
     nl,
     write('value:'),
     read(Y),
     nl.
end_of_file.

Answer 1

I was able to run this program just fine (I have GNU Prolog 1.3.0). (Although it does not fully fullfill your specifications, it's not quite done yet).

Like this, here's how it runs like :

me@consoleterminal$> prolog
GNU Prolog 1.3.0
By Daniel Diaz
Copyright (C) 1999-2007 Daniel Diaz
| ?- ['/home/myfolder/myprogram.pl'].
compiling /home/myfolder/myprogram.pl for byte code...
/home/myfolder/myprogram.pl:1-7: warning: singleton variables [X,Y] for start/0
/home/myfolder/myprogram.pl compiled, 8 lines read - 533 bytes written, 5 ms

yes
| ?- start.
input:3.

value:3.


yes
| ?-