[Topics in Combinatorics] Lecture 19. Square ice

From a channel Lumen includes in full: Every sampled title and transcript is a university mathematics lecture by a professor, covering combinatorics, discrete math, orthogonal polynomials, Lie theory and representation theory. The videos consist of definitions, theorems, proofs and worked examples with no entertainment, promotion or clickbait. Even the outlier, a VS Code LaTeX setup tutorial, is pure instruction.