View Compilation Error

0_0_20671039_6853.cpp: In function 'void mul(int (*)[30], int (*)[30])':
0_0_20671039_6853.cpp:36:10: error: 'j' was not declared in this scope
   tmp[i][j] = (tmp[i][j] + a[i][k] * b[k][j]) % 2008;
          ^