View Compilation Error

0_0_6885081_2825.cpp: In function `int InnerCircleTangent(C, C, P&, P&, P&, P&)':
0_0_6885081_2825.cpp:64: error: no match for 'operator-' in 'b - a'
GCC/bin/../lib/gcc/mingw32/3.4.2/../../../../include/c++/3.4.2/bits/stl_bvector.h:180: note: candidates are: ptrdiff_t std::operator-(const std::_Bit_iterator_base&, const std::_Bit_iterator_base&)
0_0_6885081_2825.cpp:64: error: `sqr' undeclared (first use this function)
0_0_6885081_2825.cpp:64: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6885081_2825.cpp:68: error: no match for 'operator==' in 'ap1 == bp1'
0_0_6885081_2825.cpp:74: error: no match for 'operator==' in 'ap2 == bp2'