View Compilation Error

0_0_39233299_23832.cpp: In member function 'bool patient::operator<(const patient&) const':
0_0_39233299_23832.cpp:9:50: error: 'x' was not declared in this scope
    9 |                 return pri<a.pri||pri==a.pri&&id>x.id;
      |                                                  ^