Function: minus(gradient[1](product(square(numbers('yyx') if numbers('epe') > numbers("xxx") else numbers("xxr")), numbers("xxr") if numbers("xxx") > numbers('epe') else numbers('yyx'))), product(square(numbers('epe') if numbers('yyx') > numbers("xxr") else numbers("xxx")), numbers("xxr") if numbers('epe') > numbers('yyx') else numbers("xxx")))
