Function: gradient[0](2 *(numbers("yyy"))) if minus(minus(invert(gradient[0](2 *(numbers("yyy")))), gradient[0](2 *(numbers("yyy")))), invert(gradient[0](2 *(numbers("yyy"))))) > minus(invert(gradient[0](2 *(numbers("yyy")))), gradient[0](2 *(numbers("yyy")))) else invert(gradient[0](2 *(numbers("yyy"))))
