We ask users to provide proof(s), reference(s) to proof(s), or further clarification on the proof(s) in this space.
& : logical and
: -Racah polynomial : http://dlmf.nist.gov/18.28#E19
: cosine function : http://dlmf.nist.gov/4.14#E2
Equation in Section 14.2 of KLS.
We ask users to provide relevant URL links in this space.