let x, y, c be set ; :: thesis: 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) . [<*x,y*>,'&' ] = a1 '&' a2 & (Following s) . [<*y,c*>,'&' ] = a2 '&' a3 & (Following s) . [<*c,x*>,'&' ] = a3 '&' a1 )
let s be State of (MajorityCirc x,y,c); :: thesis: for a1, a2, a3 being Element of BOOLEAN st a1 = s . x & a2 = s . y & a3 = s . c holds
( (Following s) . [<*x,y*>,'&' ] = a1 '&' a2 & (Following s) . [<*y,c*>,'&' ] = a2 '&' a3 & (Following s) . [<*c,x*>,'&' ] = a3 '&' a1 )
let a1, a2, a3 be Element of BOOLEAN ; :: thesis: ( a1 = s . x & a2 = s . y & a3 = s . c implies ( (Following s) . [<*x,y*>,'&' ] = a1 '&' a2 & (Following s) . [<*y,c*>,'&' ] = a2 '&' a3 & (Following s) . [<*c,x*>,'&' ] = a3 '&' a1 ) )
assume A1: ( a1 = s . x & a2 = s . y & a3 = s . c ) ; :: thesis: ( (Following s) . [<*x,y*>,'&' ] = a1 '&' a2 & (Following s) . [<*y,c*>,'&' ] = a2 '&' a3 & (Following s) . [<*c,x*>,'&' ] = a3 '&' a1 )
set S = MajorityStr x,y,c;
A2: InnerVertices (MajorityStr x,y,c) = the carrier' of (MajorityStr x,y,c) by FACIRC_1:37;
A3: dom s = the carrier of (MajorityStr x,y,c) by CIRCUIT1:4;
A4: ( x in the carrier of (MajorityStr x,y,c) & y in the carrier of (MajorityStr x,y,c) & c in the carrier of (MajorityStr x,y,c) ) by FACIRC_1:72;
[<*x,y*>,'&' ] in InnerVertices (MajorityStr x,y,c) by FACIRC_1:73;
hence (Following s) . [<*x,y*>,'&' ] = '&' . (s * <*x,y*>) by A2, FACIRC_1:35
.= '&' . <*a1,a2*> by A1, A3, A4, FINSEQ_2:145
.= a1 '&' a2 by FACIRC_1:def 6 ;
:: thesis: ( (Following s) . [<*y,c*>,'&' ] = a2 '&' a3 & (Following s) . [<*c,x*>,'&' ] = a3 '&' a1 )
[<*y,c*>,'&' ] in InnerVertices (MajorityStr x,y,c) by FACIRC_1:73;
hence (Following s) . [<*y,c*>,'&' ] = '&' . (s * <*y,c*>) by A2, FACIRC_1:35
.= '&' . <*a2,a3*> by A1, A3, A4, FINSEQ_2:145
.= a2 '&' a3 by FACIRC_1:def 6 ;
:: thesis: (Following s) . [<*c,x*>,'&' ] = a3 '&' a1
[<*c,x*>,'&' ] in InnerVertices (MajorityStr x,y,c) by FACIRC_1:73;
hence (Following s) . [<*c,x*>,'&' ] = '&' . (s * <*c,x*>) by A2, FACIRC_1:35
.= '&' . <*a3,a1*> by A1, A3, A4, FINSEQ_2:145
.= a3 '&' a1 by FACIRC_1:def 6 ;
:: thesis: verum