saddle-stalingrad.vlad

(include "common-stalingrad")

(let* ((start (list (real 1) (real 1)))
       (f (lambda (x1 y1 x2 y2)
	   (- (+ (sqr x1) (sqr y1)) (+ (sqr x2) (sqr y2)))))
       ((list x1* y1*)
	(multivariate-argmin
	 (lambda ((list x1 y1))
	  (multivariate-max (lambda ((list x2 y2)) (f x1 y1 x2 y2)) start))
	 start))
       ((list x2* y2*)
	(multivariate-argmax (lambda ((list x2 y2)) (f x1* y1* x2 y2)) start)))
 (list (list (write-real x1*) (write-real y1*))
       (list (write-real x2*) (write-real y2*))))