0: c <- a - c 1: IF b <= 7 THEN 2: IF a == d THEN 3: b <- a 4: a <- b GOTO 7 ELSE GOTO 2 FI ELSE 5: a <- d 6: IF d <= b THEN GOTO 5 ELSE 7: c <- b 8: d <- c 9: d <- b GOTO 0 FI FI