iintersecta([], _, _) :- !, fail.
iintersecta(AS, BS, Inter) :- append(AS, _, BS), length(AS, L), L >= 4, Inter = BS. % string_concat
iintersecta([A|AS], BS, Inter) :- iintersecta(AS, BS, IInter), Inter = [A|IInter].

intersecta(AS, BS, Inter) :- iintersecta(AS, BS, Inter), !.
intersecta(AS, BS, Inter) :- iintersecta(BS, AS, Inter), !.

string_iintersecta([], _, _) :- !, fail.
string_iintersecta(AS, BS, Inter) :- string_concat(AS, _, BS), string_length(AS, L), L >= 4, Inter = BS. % string_concat
string_iintersecta([A|AS], BS, Inter) :- iintersecta(AS, BS, IInter), Inter = [A|IInter].