$ repeat(0,_) :- !.
$ repeat(N,B) :- call(B), minus(N,1,N1), repeat(N1,B).

$ proc1([X|L]) :- repeat(5,write(X)), freeze(L,proc1(L)).

$ proc2([X|L]) :- repeat(5,write(oh)), nl, freeze(L,proc2(L)).

$ produce(N,[N|L]) :- plus(N,1,N1), produce(N1,L).

$ go :- freeze(L,proc1(L)), freeze(L,proc2(L)), produce(1,L).