#!/usr/bin/ruby var x = 3 var y = 4 assert_eq(-x, -3) assert_eq(-y, -4) assert_eq(+(3)-4, -1) assert_eq(-(x)-y, -7) assert_eq(-(x)-(4), -7) assert_eq([-(3)+4], [1]) assert_eq([-(3)-4], [-7]) assert_eq(@(1..9)-[3,5], [1,2,4,6,7,8,9]) say "** Test passed!"