saddle-smlnj.sml

fun saddle _ = let val start = [(Base 1.0), (Base 1.0)]
	           fun f x1 y1 x2 y2 = ((sqr x1)+(sqr y1))-((sqr x2)+(sqr y2))
		   val [x1_star, y1_star] =
		       multivariate_argmin
			   (fn [x1, y1] =>
			       multivariate_max
				   (fn [x2, y2] => f x1 y1 x2 y2)
				   start)
			   start
		   val [x2_star, y2_star] =
		       multivariate_argmax
			   (fn [x2, y2] => f x1_star y1_star x2 y2)
			   start
	       in [[(write x1_star), (write y1_star)],
		   [(write x2_star), (write y2_star)]];
                  0
	       end