let x, y, c be non pair object ; for s being State of (MajorityCirc (x,y,c))
for a1, a2, a3 being Element of BOOLEAN st a1 = s . x & a2 = s . y & a3 = s . c holds
( (Following (s,2)) . (MajorityOutput (x,y,c)) = ((a1 '&' a2) 'or' (a2 '&' a3)) 'or' (a3 '&' a1) & (Following (s,2)) . [<*x,y*>,'&'] = a1 '&' a2 & (Following (s,2)) . [<*y,c*>,'&'] = a2 '&' a3 & (Following (s,2)) . [<*c,x*>,'&'] = a3 '&' a1 )
set S = MajorityStr (x,y,c);
reconsider x9 = x, y9 = y, c9 = c as Vertex of (MajorityStr (x,y,c)) by Th72;
let s be State of (MajorityCirc (x,y,c)); for a1, a2, a3 being Element of BOOLEAN st a1 = s . x & a2 = s . y & a3 = s . c holds
( (Following (s,2)) . (MajorityOutput (x,y,c)) = ((a1 '&' a2) 'or' (a2 '&' a3)) 'or' (a3 '&' a1) & (Following (s,2)) . [<*x,y*>,'&'] = a1 '&' a2 & (Following (s,2)) . [<*y,c*>,'&'] = a2 '&' a3 & (Following (s,2)) . [<*c,x*>,'&'] = a3 '&' a1 )
set xy = [<*x,y*>,'&'];
set yc = [<*y,c*>,'&'];
set cx = [<*c,x*>,'&'];
A1:
Following (s,2) = Following (Following s)
by Th15;
let a1, a2, a3 be Element of BOOLEAN ; ( a1 = s . x & a2 = s . y & a3 = s . c implies ( (Following (s,2)) . (MajorityOutput (x,y,c)) = ((a1 '&' a2) 'or' (a2 '&' a3)) 'or' (a3 '&' a1) & (Following (s,2)) . [<*x,y*>,'&'] = a1 '&' a2 & (Following (s,2)) . [<*y,c*>,'&'] = a2 '&' a3 & (Following (s,2)) . [<*c,x*>,'&'] = a3 '&' a1 ) )
assume A2:
( a1 = s . x & a2 = s . y & a3 = s . c )
; ( (Following (s,2)) . (MajorityOutput (x,y,c)) = ((a1 '&' a2) 'or' (a2 '&' a3)) 'or' (a3 '&' a1) & (Following (s,2)) . [<*x,y*>,'&'] = a1 '&' a2 & (Following (s,2)) . [<*y,c*>,'&'] = a2 '&' a3 & (Following (s,2)) . [<*c,x*>,'&'] = a3 '&' a1 )
A3:
(Following s) . [<*c,x*>,'&'] = a3 '&' a1
by A2, Lm2;
( (Following s) . [<*x,y*>,'&'] = a1 '&' a2 & (Following s) . [<*y,c*>,'&'] = a2 '&' a3 )
by A2, Lm2;
hence
(Following (s,2)) . (MajorityOutput (x,y,c)) = ((a1 '&' a2) 'or' (a2 '&' a3)) 'or' (a3 '&' a1)
by A1, A3, Th79; ( (Following (s,2)) . [<*x,y*>,'&'] = a1 '&' a2 & (Following (s,2)) . [<*y,c*>,'&'] = a2 '&' a3 & (Following (s,2)) . [<*c,x*>,'&'] = a3 '&' a1 )
y in InputVertices (MajorityStr (x,y,c))
by Th74;
then A4:
(Following s) . y9 = s . y
by CIRCUIT2:def 5;
c in InputVertices (MajorityStr (x,y,c))
by Th74;
then A5:
(Following s) . c9 = s . c
by CIRCUIT2:def 5;
x in InputVertices (MajorityStr (x,y,c))
by Th74;
then
(Following s) . x9 = s . x
by CIRCUIT2:def 5;
hence
( (Following (s,2)) . [<*x,y*>,'&'] = a1 '&' a2 & (Following (s,2)) . [<*y,c*>,'&'] = a2 '&' a3 & (Following (s,2)) . [<*c,x*>,'&'] = a3 '&' a1 )
by A2, A4, A5, A1, Lm2; verum