let S1, S2, S be non empty non void Circuit-like ManySortedSign ; ( InputVertices S1 misses InnerVertices S2 & S = S1 +* S2 implies for C1 being non-empty Circuit of S1
for C2 being non-empty Circuit of S2
for C being non-empty Circuit of S st C1 tolerates C2 & C = C1 +* C2 holds
for s1 being State of C1
for s2 being State of C2
for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable )
assume that
A1:
InputVertices S1 misses InnerVertices S2
and
A2:
S = S1 +* S2
; for C1 being non-empty Circuit of S1
for C2 being non-empty Circuit of S2
for C being non-empty Circuit of S st C1 tolerates C2 & C = C1 +* C2 holds
for s1 being State of C1
for s2 being State of C2
for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable
let C1 be non-empty Circuit of S1; for C2 being non-empty Circuit of S2
for C being non-empty Circuit of S st C1 tolerates C2 & C = C1 +* C2 holds
for s1 being State of C1
for s2 being State of C2
for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable
let C2 be non-empty Circuit of S2; for C being non-empty Circuit of S st C1 tolerates C2 & C = C1 +* C2 holds
for s1 being State of C1
for s2 being State of C2
for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable
let C be non-empty Circuit of S; ( C1 tolerates C2 & C = C1 +* C2 implies for s1 being State of C1
for s2 being State of C2
for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable )
assume A3:
( C1 tolerates C2 & C = C1 +* C2 )
; for s1 being State of C1
for s2 being State of C2
for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable
let s1 be State of C1; for s2 being State of C2
for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable
let s2 be State of C2; for s being State of C st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable holds
s is stable
let s be State of C; ( s1 = s | the carrier of S1 & s2 = s | the carrier of S2 & s1 is stable & s2 is stable implies s is stable )
assume that
A4:
( s1 = s | the carrier of S1 & s2 = s | the carrier of S2 )
and
A5:
s1 is stable
and
A6:
s2 is stable
; s is stable
( dom s = the carrier of S & the carrier of S = the carrier of S1 \/ the carrier of S2 )
by A2, CIRCCOMB:def 2, CIRCUIT1:3;
then
s = s2 +* s1
by A4, FUNCT_4:70;
then s =
(Following s2) +* s1
by A6, CIRCUIT2:def 6
.=
(Following s2) +* (Following s1)
by A5, CIRCUIT2:def 6
.=
Following s
by A1, A2, A3, A4, CIRCCOMB:33
;
hence
s = Following s
; CIRCUIT2:def 6 verum