(defun x (a b ::: r)
	
	| x y |

	(set x a)
	(set y b)

	(if (> a b)
		(do
			| a b |
			(set a (mod x y))
			(set b (+ x y))
			(set r (* a b))
		)
	else
		(do

			| a b |
			(set a (* x y))
			(set b (- x y))
			(set r (* a b))
		)
	)

	(if (/= x a) (printf "ERROR: x is not equal to a\n"))
	(if (/= y b) (printf "ERROR: y is not equal to b\n"))
)

(set t (x 10 20))
(if (/= t -2000) (printf "ERROR: t is not equal to -2000\n")
 else (printf "OK: %d\n" t))
(set t (x 30 20))
(if (/= t 500) (printf "ERROR: t is not equal to 500\n")
 else (printf "OK: %d\n" t))


(defun x ()

	(do
		| x y |

		(set x 99)
		(try

			(do
				| x |
				(set x 88)
				(if (/= x 88) (printf "ERROR: x is not 88\n")
		 	 	 else (printf "OK: %d\n" x))
				(throw 1000)
			)
		catch (x)
			(if (/= x 1000) (printf "ERROR: x is not 1000\n")
		 	 else (printf "OK: %d\n" x))
			(set y x)
		)	

		(if (/= x 99) (printf "ERROR: x is not 99\n")
		 else (printf "OK: %d\n" x))
		(if (/= y 1000) (print "ERROR: y is not 1000\n")
		 else (printf "OK: %d\n" y))
	)
) 

(x)