View Compilation Error

0_0_11725254_10511.cpp: In function `Matrix matrixPow(Matrix, int)':
0_0_11725254_10511.cpp:38: error: `mul' undeclared (first use this function)
0_0_11725254_10511.cpp:38: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_11725254_10511.cpp: In function `int main()':
0_0_11725254_10511.cpp:50: error: 'struct Matrix' has no member named 'mat'
0_0_11725254_10511.cpp:55: error: 'struct Matrix' has no member named 'mat'
0_0_11725254_10511.cpp:64: error: 'struct Matrix' has no member named 'mat'