Function: gradient[2](invert(product(minus(numbers('xry'), numbers('rep')), numbers('xry'))) if round(invert(product(minus(numbers('xry'), numbers('rep')), numbers('xry'))), product(minus(numbers('xry'), numbers('rep')), numbers('xry'))) > product(minus(numbers('xry'), numbers('rep')), numbers('xry')) else minus(numbers('xry'), numbers('rep')))
