let M be non empty MidStr ; for p, q being Point of M
for G being non empty right_complementable add-associative right_zeroed addLoopStr
for w being Function of [: the carrier of M, the carrier of M:], the carrier of G st w is_atlas_of the carrier of M,G & w is associating holds
p @ q = q @ p
let p, q be Point of M; for G being non empty right_complementable add-associative right_zeroed addLoopStr
for w being Function of [: the carrier of M, the carrier of M:], the carrier of G st w is_atlas_of the carrier of M,G & w is associating holds
p @ q = q @ p
let G be non empty right_complementable add-associative right_zeroed addLoopStr ; for w being Function of [: the carrier of M, the carrier of M:], the carrier of G st w is_atlas_of the carrier of M,G & w is associating holds
p @ q = q @ p
let w be Function of [: the carrier of M, the carrier of M:], the carrier of G; ( w is_atlas_of the carrier of M,G & w is associating implies p @ q = q @ p )
assume that
A1:
w is_atlas_of the carrier of M,G
and
A2:
w is associating
; p @ q = q @ p
set r = p @ q;
w . (p,(p @ q)) = w . ((p @ q),q)
by A2;
then
w . ((p @ q),p) = w . (q,(p @ q))
by A1, Th5;
hence
p @ q = q @ p
by A2; verum