: sign-test
  DUP 0 > IF ." positive" ELSE DUP 0 < IF ." negative" ELSE ." zero" THEN THEN CR
;
: sumto
  0 SWAP 1 DO I + LOOP
;
: countdown
  BEGIN DUP . 1- DUP 0 = UNTIL DROP CR
;
: countup
  0 BEGIN DUP 5 < WHILE DUP . 1+ REPEAT DROP CR
;
5 sign-test
0 sign-test
-3 sign-test
5 sumto . CR
5 countdown
countup
0 BYE
