The galerkin / petrov - least squares - type mixed finite element method and the nonlinear galerkin / petrov - least squares mixed element method so that they are stable for any combination of discrete finite element spaces without requiring the babuska - brezzi stability condition Galerkin / petrov最小二乘混合元法和非线性galerkin / petrov最小二乘混合元法使得有限元空间之间的组合无需满足离散的babuka - brezzi稳定性条件，从而使得它们的有限元空间可以任意选择。
