let L be non empty left_unital doubleLoopStr ; for n being non empty Nat
for i being Nat st i <> 0 & i <> n holds
(unital_poly L,n) . i = 0. L
let n be non empty Nat; for i being Nat st i <> 0 & i <> n holds
(unital_poly L,n) . i = 0. L
let i be Nat; ( i <> 0 & i <> n implies (unital_poly L,n) . i = 0. L )
assume that
A1:
i <> 0
and
A2:
i <> n
; (unital_poly L,n) . i = 0. L
set p = (0_. L) +* 0 ,(- (1_ L));
A3:
i in NAT
by ORDINAL1:def 13;
(((0_. L) +* 0 ,(- (1_ L))) +* n,(1_ L)) . i =
((0_. L) +* 0 ,(- (1_ L))) . i
by A2, FUNCT_7:34
.=
(0_. L) . i
by A1, FUNCT_7:34
.=
0. L
by A3, FUNCOP_1:13
;
hence
(unital_poly L,n) . i = 0. L
; verum