Q. (+ (10) 20)
procedure application: expected procedure, given: 10 (no arguments)

A. Numbers should not be included in parenthesis.


Q. (10 + 20)
procedure application: expected procedure, given: 10; arguments were: + 20

A. The operator must be mentioned first.


Q. (+ +)
procedure +: expects at least 2 arguments, given 1: +

A. Only one operator can reside within a parenthesis.