int GridCreateVarOrdering_Triangular_2D(Grid, FieldClassMap, VarOrdering *);
int GridCreateLocalVarOrdering_Triangular_2D(Grid, int, int *, LocalVarOrdering *);
int GridVarOrderingConstrain_Triangular_2D(Grid, int, PetscConstraintObject, FieldClassMap, VarOrdering, VarOrdering *);
int GridCreateVarScatter_Triangular_2D(Grid, VarOrdering, GVec, VarOrdering, GVec, VecScatter *);