let S1, S2, S be non empty non void Circuit-like ManySortedSign ; ( InnerVertices S2 misses InputVertices S1 & S = S1 +* S2 implies for A1 being non-empty Circuit of S1
for A2 being non-empty Circuit of S2
for A being non-empty Circuit of S st A1 tolerates A2 & A = A1 +* A2 holds
for s being State of A
for s1 being State of A1
for s2 being State of A2 st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 holds
Following s = (Following s2) +* (Following s1) )
assume that
A1:
InnerVertices S2 misses InputVertices S1
and
A2:
S = S1 +* S2
; for A1 being non-empty Circuit of S1
for A2 being non-empty Circuit of S2
for A being non-empty Circuit of S st A1 tolerates A2 & A = A1 +* A2 holds
for s being State of A
for s1 being State of A1
for s2 being State of A2 st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 holds
Following s = (Following s2) +* (Following s1)
let A1 be non-empty Circuit of S1; for A2 being non-empty Circuit of S2
for A being non-empty Circuit of S st A1 tolerates A2 & A = A1 +* A2 holds
for s being State of A
for s1 being State of A1
for s2 being State of A2 st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 holds
Following s = (Following s2) +* (Following s1)
let A2 be non-empty Circuit of S2; for A being non-empty Circuit of S st A1 tolerates A2 & A = A1 +* A2 holds
for s being State of A
for s1 being State of A1
for s2 being State of A2 st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 holds
Following s = (Following s2) +* (Following s1)
let A be non-empty Circuit of S; ( A1 tolerates A2 & A = A1 +* A2 implies for s being State of A
for s1 being State of A1
for s2 being State of A2 st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 holds
Following s = (Following s2) +* (Following s1) )
assume that
A3:
A1 tolerates A2
and
A4:
A = A1 +* A2
; for s being State of A
for s1 being State of A1
for s2 being State of A2 st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 holds
Following s = (Following s2) +* (Following s1)
S1 tolerates S2
by A3, Def3;
then A5:
S = S2 +* S1
by A2, Th9;
A = A2 +* A1
by A3, A4, Th26;
hence
for s being State of A
for s1 being State of A1
for s2 being State of A2 st s1 = s | the carrier of S1 & s2 = s | the carrier of S2 holds
Following s = (Following s2) +* (Following s1)
by A1, A3, A5, Th23, Th39; verum