:- op(500,xf,was).
:- op(400,fy,the).
:- op(300,xf,of).

john was the secretary of the department.


:- op(400,fx,deletingop).
:- op(300,xfx,from).
:- op(200,xfy,gives).
deletingop Item from [Item] gives [].
deletingop Item from [Item|Tail] gives Result :- deletingop Item from Tail gives Result,!.
deletingop Item from [Head|Tail] gives Result :- deletingop Item from Tail gives R1,append([Head],R1,Result).


squares :- print("Enter a number:"),read(Number),nl,Result is Number*Number,writef("%w^2 = %w",[Number,Result]),nl,squares.

writelist([]).
writelist([Head|Tail]) :- print(Head),write(' '),writelist(Tail).