(module saddle-RR-bigloo (include "common-bigloo.sc"))
(define (run)
(let* ((start (list 1.0 1.0))
(f (lambda (x1 y1 x2 y2)
(d- (d+ (sqr x1) (sqr y1)) (d+ (sqr x2) (sqr y2)))))
(x1*-y1*
(multivariate-argmin-R
(lambda (x1-y1)
(multivariate-max-R
(lambda (x2-y2)
(f (car x1-y1) (car (cdr x1-y1)) (car x2-y2) (car (cdr x2-y2))))
start))
start))
(x1* (car x1*-y1*))
(y1* (car (cdr x1*-y1*)))
(x2*-y2*
(multivariate-argmax-R
(lambda (x2-y2) (f x1* y1* (car x2-y2) (car (cdr x2-y2)))) start))
(x2* (car x2*-y2*))
(y2* (car (cdr x2*-y2*))))
(list (list (write-real x1*) (write-real y1*))
(list (write-real x2*) (write-real y2*)))))
(run)