go :- hypothesize(Coffee),
  write('Your order is : '),
  write(Coffee),
  write('and the price for your order =  : ')
  nl,
  undo.

    /* hypotheses to be tested */
  hypothesize(moca)   :- moca, !.
  hypothesize(hotChocolate)     :- hotChocolate, !.
  hypothesize(latte)   :- latte, !.
   hypothesize(cappuccino)     :- cappuccino, !.

  /*   rules */
  moca :-
      /* ask if you want hot or cold
       * ask the size of the coffee*/