solve
static bool solve(const double left[Size][Size],
m_valid = simul_eq<4, 2>::solve(left, right, m_mtx);
bool success = solve(aa, aam, lambda);
success = solve(fTemp2, zn, pz);
if (!solve(system))
bool success = solve(aa, aam, lambda);
success = solve(fTemp2, zn, pz);