mathlib

cdb7af2f - feat(combinatorics/simple_graph): add three useful lemmas relating walk.support and walk.append (#15687)

feat(combinatorics/simple_graph): add three useful lemmas relating walk.support and walk.append (#15687) Co-authored-by: Kyle Miller <kmill31415@gmail.com> Co-authored-by: Kyle Miller <kmill31415@gmail.com>