mathlib

8efb93b1 - feat(combinatorics/simple_graph/strongly_regular): add definition of strongly regular graph and proof that complete graph is SRG (#7044)

feat(combinatorics/simple_graph/strongly_regular): add definition of strongly regular graph and proof that complete graph is SRG (#7044) Add definition of strongly regular graph and proof that complete graphs are strongly regular. Part of #5698 to prove facts about strongly regular graphs. Co-authored-by: agusakov <39916842+agusakov@users.noreply.github.com>