lexpr minus -
lexpr times *
lexpr divide /
-lexpr mod %
+lexpr modulo modulo %
+lexpr remainder
+lexpr quotient
lexpr equal = eq? eqv?
lexpr less <
lexpr greater >
lambda not
lambda listp list?
lambda pairp pair?
+lambda numberp number? integer?
+lambda booleanp boolean?
+lambda set_car set-car!
+lambda set_cdr set-cdr!