Function: gradient[1](sum(sqrt(sum(minus(numbers("yyy") if numbers("yxx") > numbers("xxy") else numbers('epe'), numbers('epe')), numbers('epe') if numbers("yyy") > numbers("yxx") else numbers("xxy"))), sum(minus(numbers("xxy") if numbers("yyy") > numbers('epe') else numbers("yxx"), numbers('epe')), numbers('epe') if numbers("xxy") > numbers("yyy") else numbers("yxx"))))
