Bug re: \+ operator

[Jules Altfas]

Hello,

If you already know about this problem, good!

In gprolog 1.2.5, I used the following goal:
        
        ...,
        \+ (0 is (Y mod 4)),
        ...,

Obviously, if "Y mod 4" is other than 0, it should succeed.  When I ran
this in the top-level interpreter, in fact it worked as expected, but not
when compiled.  In the compiled version, this goal would succeed but I
always got the message:

        
"system_error(cannot_catch_throw(error(existence_error(procedure,(is)/2),(\+)/1)))"

This didn't seem to be a problem in gprolog 1.2.4.  I was able to use a
work-around in 1.2.5 for compiled code with
        
        ...,
        M is (Y mod 4),
        M \= 0, ...

At any rate, I really like the compiler and appreciate all the hard work
that's gone into it.

Thanks,
Jules R. Altfas.