How does this program work in Prolog?

Question

Prolog

Given a program in Prolog. Can you please explain how it works?

count(_,[],0).

count(X,[X|L],N):-count(X,L,N2),N is N2 + 1.

count(X,[_|L],N):-count(X,L,N).
p([],_,[]).
p([X|V],N,[X|L]):-count(X,[X|V],K),K >= N, delete(V,X,V2),p(V2,N,L).

p([X|V],N,L):-delete(V,X,V2),p(V2,N,L).

This program removes from the input list all elements that appear in this list more than N times.