let K be Field; for i being Element of NAT holds 1. (K,<*i*>) = <*(1. (K,i))*>
let i be Element of NAT ; 1. (K,<*i*>) = <*(1. (K,i))*>
A1: dom (1. (K,<*i*>)) =
dom <*i*>
by Def8
.=
Seg 1
by FINSEQ_1:38
;
then
1 in dom (1. (K,<*i*>))
;
then A2: (1. (K,<*i*>)) . 1 =
1. (K,(<*i*> . 1))
by Def8
.=
1. (K,i)
;
len (1. (K,<*i*>)) = 1
by A1, FINSEQ_1:def 3;
hence
1. (K,<*i*>) = <*(1. (K,i))*>
by A2, FINSEQ_1:40; verum