gistfile1.txt

    (
      (def roof (bigx bigz smallx smallz y m)
        (if (eq bigx smallx) unit
          (begin
            (corners (loc bigx y bigz) (loc smallx y smallz))
            (setall m)
            (roof (- bigx 1) (- bigz 1) (+ smallx 1) (+ smallz 1) (+ 1 y) m)
          )
        )
      )
      (def house (w h d)
        (begin
          (corners (loc w (+ Y h) d) (loc (- 0 w) Y (- 0 d)))
          (setall (material "air"))
          ; build walls and floor
          (floor (material "stone"))
          (walls (material "brick"))
          ; build roof
          (roof (+ 1 w) (+ 1 d) (- -1 w) (- -1 d) (+ Y h 1) (material "wood"))
        )
      )
      (house 5 8 5)
    )