VAL INT screen.width IS 80:
VAL INT screen.height IS 24:

PROC clear.buffer ([screen.height][screen.width]BYTE screen, [screen.height][screen.width]INT colour)
  SKIP
:

PROC screen.buffer (CHAN OF BYTE in, CHAN OF BYTE out)
  [2][screen.height][screen.width]BYTE screen:
  [2][screen.height][screen.width]INT colour:
  SEQ
    clear.buffer (screen[0], colour[0])
    clear.buffer (screen[1], colour[1])
:

PROC q7 ()
  SKIP
: