I am new to Prolog and using the SWISH SWI online PROLOG website. https://swish.swi-prolog.org/
I am trying a really basic program:
a('jae'). b('lii'). c('jackson'). happy(A):-sings(A). happy(B):-dances(B). goToPlay(C):-free(C).
trying to run happy(jae). gives the following error
procedure `sings(A)' does not exist Reachable from: happy(A)
Please help me solve this.
If submit the goal
happy(A) :- sings(A).
applies, which means that the next goal to be solved is
Unfortunately the one-argument predicate
sings/1 is nowhere to be found, so you get the same error as for a missing procedure in another programming language.
You have to define