#lang racket (require (planet wcy/mpost-wrapper)) (provide main) (define (main) (let ((A (point '-1.5cm '-1.5cm)) (B (point '1.5cm '-1.5cm)) (C (point '1.5cm '1.5cm)) (D (point '-1.5cm '1.5cm))) (fill (op-- A C B D 'cycle) #:withcolor (op* 0.8 'white)) (draw (op-- (point '-1.5cm 0) (point '1.5cm '0))) (draw (op-- (point 0 '-1.5cm) (point 0 '1.5cm))) (drawarrow (op-- (point 0 0) (point '1cm 0)) #:withpen (scale '2bp 'pencircle)) (drawarrow (op-- (point 0 0) (point 0 '1cm)) #:withpen (scale '2bp 'pencircle))))