let n be set ; for L being non empty right_complementable add-associative right_zeroed addLoopStr
for p being Series of n,L holds p - p = 0_ (n,L)
let L be non empty right_complementable add-associative right_zeroed addLoopStr ; for p being Series of n,L holds p - p = 0_ (n,L)
let p be Series of n,L; p - p = 0_ (n,L)
reconsider pp = p - p, Z = 0_ (n,L) as Function of (Bags n), the carrier of L ;
hence
p - p = 0_ (n,L)
; verum