Lists in Prolog

• Elements of lists are any valid Prolog data object
• Elements are terms separated by commas, do not have to be same type
• Vertical bar separates head (first) from tail (rest)
• The head of [john, mary, pat] is john
• The tail of [john, mary, pat] is [mary, pat]
• The representation of the combination is Head | Tail (in our example, [john | [mary, pat]] or [john | [mary | [pat | []]]])
• Member function

  member(X, L) :- L = [X|_].
  member(X, L) :- L = [A|B], member(X,B).