Topology

L1,L2,LX 2D Curve

T1,T2,TX 2D Triangle

Q1, Q2, Q2S, QX 2D Quadrilateral

C1, C2, CX 3D curve

P1, P2, PX 3D triangle surface

S1, S2, S2S, SX 3D quadrilateral surface

O1, O2, OX Tetrahedron

H1, H2, H2S, HX Hexahedron