Second Alternate
(less desirable)
lUse a conditional guard:
lmember(X, [ ]) => 0;
lmember(X, [F| R]) => (X == F) ? 1;

lmember(X, [F| R]) => member(X, R);

lThe condition is tested after any other matching is applied.
lIf the condition fails, then subsequent rules are tried.
conditional guard