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
by FUNCT_2:113; verum