View Compilation Error

0_0_37737123_23268.cpp: In function 'bool check()':
0_0_37737123_23268.cpp:30:22: error: 'check1' was not declared in this scope
   if(check1(x[1],y[i])) return 1;
                      ^
0_0_37737123_23268.cpp:31:32: error: 'check1' was not declared in this scope
   if(check1(x[1],y[i]+x[1]-x[i])) return 1;
                                ^
0_0_37737123_23268.cpp:32:32: error: 'check1' was not declared in this scope
   if(check1(x[1],y[i]+x[i]-x[1])) return 1;
                                ^