(defun grade (student)
(cond ((excellent-work student) :a+)
((okay-stuff student) (if (tried-hard student) :b :b-))
(t :c))) (defun grade (student)
(cond ((excellent-work student) :a+)
((okay-stuff student) (if (tried-hard student) :b :b-))
(t :c))) grade(#student{work=Work, tried_hard=Tried}) -> grade1(Work, Tried).
grade1(excellent_work, _) -> 'a+';
grade1(okay_stuff, yes) -> b;
grade1(okay_stuff, _) -> 'b-';
grade1(_, _) -> c.
grade(Student, Grade) :-
worked(Student, Work), work_grade(Work, Student, Grade).
work_grade('Excellent', _, 'A+').
work_grade('Okay', Student, 'B') :- tried_hard(Student).
work_grade('Okay', _, 'B-').
work_grade(_, _, 'C').
dostuff(x)
(dostuff x)