exists([(Feat1-Val1)|_],Feat1,Val1):-!.
exists([_|T],Param2,K):-exists(T,Param2,K),!.

extends(_,[]):-!.
extends(A,A):-!.
extends(List1,[(Bas2-Val2) | Remain2]):- exists(List1,Bas2,X),extends(X,Val2),extends(List1,Remain2),!.

delete([],_,[]).
delete([(Feat1-_)|Remain],Feat1,Remain):-!.
delete([Mem1|Remain],Feat1,[Mem1|Kalan]):-delete(Remain,Feat1,Kalan).
 
mgu(A,A,A):-!.
mgu([],List2,List2).
mgu([(Feat1-Val1)|Remain1],List2,[(Feat1-M)|N]):- exists(List2,Feat1,X),!,mgu(Val1,X,M),delete(List2,Feat1,D),mgu(Remain1,D,N).
mgu([(Feat1-Val1)|Remain1],List2,[(Feat1-Val1)|N]):- mgu(Remain1,List2,N).
 
lgs(A,A,A):-!.
lgs([],_,[]).
lgs([(Feat1-Val1)|Remain1],List2,[(Feat1-M)|N]):- exists(List2,Feat1,X),lgs(Val1,X,M),!,lgs(Remain1,List2,N).
lgs([(Feat1-Val1)|Remain1],List2,N):- exists(List2,Feat1,X),!,lgs(Remain1,List2,N).
lgs([_|Remain1],List2,N):- lgs(Remain1,List2,N).