A1:
( <e1> . 1 = 1 & <e1> . 2 = 0 & <e1> . 3 = 0 )
by FINSEQ_1:45;
set e = |[0,0,0]|;
( |[0,0,0]| . 1 = 0 & |[0,0,0]| . 2 = 0 & |[0,0,0]| . 3 = 0 )
by FINSEQ_1:45;
then |(<e1>,|[0,0,0]|)| =
((1 * 0) + (0 * 0)) + (0 * 0)
by A1, Lm5
.=
0
;
hence
|(<e1>,|[0,0,0]|)| = 0
; verum