Expanded Mixed Finite Element Method for the Two-Dimensional Sobolev Equation

Table 1

Some RT type mixed elements.

Dim	Element	𝐕ℎ(𝐸)	𝑊ℎ(𝐸)
2D	Triangle	RT𝑘(𝑇)=𝑃𝑘(𝐸)^2⊕𝐱𝑃𝑘(𝐸)	𝑃𝑘(𝐸)
2D	Rectangle	RT[𝑘](𝑇)=𝑄𝑘+1,𝑘(𝐸)⊕𝑄𝑘,𝑘+1(𝐸)	𝑄𝑘,𝑘(𝐸)