Constructing Recursive Data Structures: Lists

  $\mbox{$\bullet$}$

Definition of membership:

member(Element, .(Element, List)).
member(Element, .(AnElement, RestList)):-
member(Element, RestList).

?- member(b, .(a, .(b, .(c, [])))).
yes

?- member(plof, .(a, .(b, .(c, [])))).
no

?- member(X, .(a, .(b, .(c, [])))).
X = a ? ;
X = b ? ;
X = c ?

?- member(a, .(a, .(X, .(c, [])))).
true ;
X = a