mathlib

e43d9649 - chore(data/pi,algebra/group/pi): reorganize proofs (#6869)

chore(data/pi,algebra/group/pi): reorganize proofs (#6869) Add `pi.single_op` and `pi.single_binop` and use them in the proofs. Co-authored-by: Eric Wieser <wieser.eric@gmail.com>