  This is the second lecture note on the error analysis of interpolation on
simplicial elements without the shape regularity assumption (the previous one
is arXiv:1908.03894). In this manuscript, we explain the error analysis of
Lagrange interpolation on (possibly anisotropic) tetrahedrons. The manuscript
is not intended to be a research paper. We hope that, in the future, it will be
merged into a textbook on the mathematical theory of the finite element
methods.
