#lang racket
(require (planet wcy/mpost-wrapper))
(provide main)
(define (main)
  (let* ((A (point 0 '1cm))
         (B (rotate 120 A))
         (p (path A (dir-spec (dir 0)) '..
                  'tension 2 '..
                  B (dir-spec (dir 120))))
         (a (unknown-numeric)))
    (eqn= (point a (whatever))
          (intersectiontimes p (rotate 120 p)))
    (draw (subpath-of 0 (op- a 0.02) p))
    (draw (subpath-of (op+ a 0.02) 1 p))
    (draw (subpath-of 0 (op- a 0.02) (rotate 120 p)))
    (draw (subpath-of (op+ a 0.02) 1 (rotate 120 p)))
    (draw (subpath-of 0 (op- a 0.02) (rotate -120 p)))
    (draw (subpath-of (op+ a 0.02) 1 (rotate -120 p)))))