replacing each element of a list by a specific list - list

Question

I try to define replaceEltByclass(E1:list,E2:list) E is a list without sublist. each element of E1 belonging to a class C is replaced by the
elements of C. The final result is put in E2. For example, the goal rep_class([e1,e4,e6,e11], E2) will provide the list E2 : [[e1,e8,e10], e4,[e3,e6,e7],e11]. I don't have the good results.
/*The code*/
/*facts*/
class(c1,[e3, e6, e7]).
class(c2,[e1, e8, e10]).
/*rules*/
rep_class([],[]).
rep_class([E|Q],E2) :-
class(C,L),
not(member(E,L)),
concat(E2,E,E2),
rep_class(Q,E2).
rep_class([E|Q],E2) :-
class(C,L),
member(E,L),
concat(E2,L,E2),
rep_class(Q,E2).
/*conventional concat*/
concat([],L,L).
concat([H|T],L,[H|Res]) :- concat(T,L,Res).

Answer 1

The problem is in: class(C,L),not(member(E,L)), because it will give two solution one if C=C2 and then for example e1 belongs in C2 so it will replace it with L and one solution when C=C1 where it will leave it as e1. You need to write "does C exists such member(e1,L)??" so you have to collect all possible lists and see if member(e1,L) stands for a list L. So with some changes my version is :
class(c1,[e3, e6, e7]).
class(c2,[e1, e8, e10]).
rep_class([],[]).
rep_class([E|Q],[E|E2]) :-
findall(L,class(_,L),List),
not(find(List,E,_)),
rep_class(Q,E2).
rep_class([E|Q],[Lout|E2]) :-
findall(L,class(_,L),List),
find(List,E,Lout),
rep_class(Q,E2).
find([Lin|_],E,Lin):-member(E,Lin).
find([Lin|T],E,Lout):-not(member(E,Lin)),find(T,E,Lout).
As an example:
?- rep_class([e1,e4,e6,e11], E2).
E2 = [[e1, e8, e10], e4, [e3, e6, e7], e11] ;
false.