A dimensional s contains a saddle point wben the point is a global minimum along a line parallel to either the x or the y axis, but a global maximum along the other axis. You'll usually see a "U" shape meeting an upside down "U" shape. The classic horseback riding saddle has one such saddle point, and, not coincidentally, it is a rider's most stable position The input will be a 2-dimensional array Aln]Inl of numbers representing a lattice approximation of a surface. That is, given an (x,y) pair of integers, the array entry Alxlly] contains the height (z-coordinate) of the surface. In the sample surface shown (thank you to Wikipedia!), the array might be: 0.50 62 0.72 o.80 0.88 0.93 o.97 0.99 1.00 o.99 0.97 0.93 0.88 0.80 0.72 0.62 0.50 0.38 0.50 0.60 0.69 0.76 0.81 0.850.88 0.88 o.88 0.850.81 0.76 o.69 o.60 o.50 o .38 0.28 0.40 0.500.59 o.660.71 0.75 0.77 0.78 0.77 0.15 o.21 o.66 590.50 0.40 0.28 0.20 0.31 0.41 o. 50 0.57 62 0.66 0.69 0.70 0.69 0.66 0.62 570. 50 o .41 o.31 0.20 0.12 0.24 0.34 o.43 o.50 o.5s o 59 o. 62 0.62 o.62 0.s90.550.50 o.43 o.34 o.24 o.12 0.07 0.19 0.29 o .38 o.450.50 0.54 0.560.57 o.56 o.54 o .50 o.4s o .38 o.29 o.19 0.07 0.03 0.15 0.25 0.34 41 0.46 0.50 0.52 0.53 0.52 0.50 0.46 0.41 0.34 o.25 0.15 0.03 0.01 0.12 0.23 0.31 0.38 44 0.48 0.50 0.51 0.50 0.48 44 0.38 0.31 0.23 0.12 0.01 0.00 0.12 0.22 0.30 0.38 0.43 0.47 0.50 0.49 0.47 0.43 0.38 0.30 0.22 0.12 0.00 0.01 0.12 0.23 0.31 0.38 0.44 0.48 0.50 0.51 0.50 0.48 0.44 0.38 0.31 0.23 0.12 0.01 0.03 0.15 0.25 0.34 0.41 46 0.50 0.52 0.53 0.52 0.50 0.46 0.41 0.34 0.25 0.15 0.03 0.07 0.19 0.29 0.38 0.45 0.50 0.54 0.56 0.57 0.56 0.54 0.50 0.45 0.38 0.29 0.19 0.07 0.12 0.24 0.34 0.43 0.50 0.55 0.59 0.62 0.62 0.62 0.59 0.55 0.50 0.43 0.34 0.24 0.12 0.20 0.31 0.41 0.50 57 0.62 0.66 0.69 0.70 0.69 0.66 0.62 0.570.50 0.41 0.31 0.20 0.28 0.40 0.50 0.59 0.66 0.71 75 0.77 0.78 0.77 0.75 0.71 0.66 0.59 0.50 0.40 o .28 0.38 0.50 0.60 0.69 0.76 0.81 0.85 0.88 0.88 0.88 0.85 0.81 0.76 0.69 o.60 0.50 0.38 0.500 0.62 0.72 0.80 0.88 0.93 0.97 0.99 1.00 0.99 0.97 0.93 0.88 0.80 0.72 0.62 0.50