/usr/share/Yap/pl/ground.yap is in yap 5.1.3-6.
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* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: ground.pl *
* Last rev: *
* mods: *
* comments: Variables and ground *
* *
*************************************************************************/
/*
% grounds all free variables
% as terms of the form '$VAR'(N)
numbervars('$VAR'(M), M, N) :- !,
succ(M, N).
numbervars(Atomic, M, M) :-
atomic(Atomic), !.
numbervars(Term, M, N) :-
functor(Term, _, Arity),
'$numbervars'(0,Arity, Term, M, N).
'$numbervars'(A, A, _, N, N) :- !.
'$numbervars'(A,Arity, Term, M, N) :-
'$succ'(A,An),
arg(An, Term, Arg),
numbervars(Arg, M, K), !,
'$numbervars'(An, Arity, Term, K, N).
ground(Term) :-
nonvar(Term), % This term is not a variable,
functor(Term, _, Arity),
'$ground'(Arity, Term). % and none of its arguments are.
'$ground'(0, _) :- !.
'$ground'(N, Term) :-
'$predc'(N,M),
arg(N, Term, ArgN),
ground(ArgN),
'$ground'(M, Term).
*/
numbervars(Term, M, N) :-
'$variables_in_term'(Term, [], L),
'$numbermarked_vars'(L, M, N).
'$numbermarked_vars'([], M, M).
'$numbermarked_vars'([V|L], M, N) :-
attvar(V), !,
'$numbermarked_vars'(L, M, N).
'$numbermarked_vars'(['$VAR'(M)|L], M, N) :-
M1 is M+1,
'$numbermarked_vars'(L, M1, N).
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