test_divisors = ->
	run_test [

		"divisors(12)",
		"(1,2,3,4,6,12)",

		"divisors(-12)",
		"(1,2,3,4,6,12)",

		"divisors(a)",
		"(1,a)",

		"divisors(-a)",
		"(1,a)",

		"divisors(+3*x+3)",
		"(1,3,1+x,3+3*x)",

		"divisors(+3*x-3)",
		"(1,3,-3+3*x,-1+x)",

		"divisors(-3*x+3)",
		"(1,3,1-x,3-3*x)",

		"divisors(-3*x-3)",
		"(1,3,1+x,3+3*x)",
	]