View Compilation Error

0_0_16555997_9862.c: In function 'fun':
0_0_16555997_9862.c:4:14: error: 'y0' undeclared (first use in this function)
  if((y%4==0&&y0!=0)||y@0==0)
              ^
0_0_16555997_9862.c:4:14: note: each undeclared identifier is reported only once for each function it appears in
0_0_16555997_9862.c:4:23: error: stray '@' in program
  if((y%4==0&&y0!=0)||y@0==0)
                       ^
0_0_16555997_9862.c:4:24: error: expected ')' before numeric constant
  if((y%4==0&&y0!=0)||y@0==0)
                        ^