View Compilation Error

0_0_29291795_20421.cpp: In function 'bool cmp1(Q, Q)':
0_0_29291795_20421.cpp:11:12: error: 'bel' was not declared in this scope
     return bel[a.l]==bel[b.l]?a.r<b.r:a.l<b.l;
            ^