let nt be NonTerminal of SCM-AE; not not nt = [0,0] & ... & not nt = [0,4]
consider x, y being object such that
A1:
x in 1
and
A2:
y in 5
and
A3:
nt = [x,y]
by Lm3, ZFMISC_1:84;
A4:
x = 0
by A1, CARD_1:49, TARSKI:def 1;
consider n being Nat such that
A5:
y = n
and
A6:
n < 5
by A2, Lm2;
5 = 4 + 1
;
then
n <= 4
by A6, NAT_1:13;
then
not not n = 0 & ... & not n = 4
;
hence
not not nt = [0,0] & ... & not nt = [0,4]
by A3, A4, A5; verum