.m_basis_heading[entr_q.front()] >= 0)                     entr_q.pop();                 if (!entr_q.empty()) {                     entering = entr_q.front();                     entr_q.pop();                 } else {                     leav_q.push(leaving);                     continue;                 }             }             lp_assert(m_r_solver.m_basis_heading[