let i1, i2, i3, i4 be Integer; for s being State of SCM st s . (dl. 0) = i1 & s . (dl. 1) = i2 & s . (dl. 2) = i3 & s . (dl. 3) = i4 holds
s is State-consisting of <%i1,i2,i3,i4%>
let s be State of SCM; ( s . (dl. 0) = i1 & s . (dl. 1) = i2 & s . (dl. 2) = i3 & s . (dl. 3) = i4 implies s is State-consisting of <%i1,i2,i3,i4%> )
assume A1:
( s . (dl. 0) = i1 & s . (dl. 1) = i2 & s . (dl. 2) = i3 & s . (dl. 3) = i4 )
; s is State-consisting of <%i1,i2,i3,i4%>
set D = <%i1,i2,i3,i4%>;
now for k being Element of NAT st k < len <%i1,i2,i3,i4%> holds
s . (dl. k) = <%i1,i2,i3,i4%> . klet k be
Element of
NAT ;
( k < len <%i1,i2,i3,i4%> implies s . (dl. k) = <%i1,i2,i3,i4%> . k )A2:
(
len <%i1,i2,i3,i4%> = 4 & 4
= 3
+ 1 )
by AFINSQ_1:84;
assume
k < len <%i1,i2,i3,i4%>
;
s . (dl. k) = <%i1,i2,i3,i4%> . kthen
k <= 3
by A2, NAT_1:13;
then
not not
k = 0 & ... & not
k = 3
;
hence
s . (dl. k) = <%i1,i2,i3,i4%> . k
by A1;
verum end;
hence
s is State-consisting of <%i1,i2,i3,i4%>
by Def1; verum