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) & 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) & p + (- p) = 0_ (n,L) )
let p be Series of n,L; ( (- p) + p = 0_ (n,L) & p + (- p) = 0_ (n,L) )
set q = (- p) + p;
hence
(- p) + p = 0_ (n,L)
by FUNCT_2:63; p + (- p) = 0_ (n,L)
set q = p + (- p);
hence
p + (- p) = 0_ (n,L)
by FUNCT_2:63; verum