' Ethiopian multiplication
PROGRAM "ethmult"
VERSION "0.0000"

DECLARE FUNCTION Entry()
INTERNAL FUNCTION Double(@a&&)
INTERNAL FUNCTION Halve(@a&&)
INTERNAL FUNCTION IsEven(a&&)

FUNCTION Entry()
  x&& = 17
  y&& = 34
  tot&& = 0
  DO WHILE x&& >= 1
    PRINT FORMAT$("#########", x&&);
    PRINT " ";
    IFF IsEven(x&&) THEN
      tot&& = tot&& + y&&
      PRINT FORMAT$("#########", y&&);
    END IF
    PRINT
    Halve(@x&&)
    Double(@y&&)
  LOOP
  PRINT "=         ";
  PRINT FORMAT$("#########", tot&&);
  PRINT
END FUNCTION

FUNCTION Double(a&&)
  a&& = 2 * a&&
END FUNCTION

FUNCTION Halve(a&&)
  a&& = a&& / 2
END FUNCTION

FUNCTION IsEven(a&&)
  RETURN a&& MOD 2 = 0
END FUNCTION
END PROGRAM