reconsider n9 = n as Element of NAT by ORDINAL1:def 12;
let S1, S2 be Symplex of T,n; ( ( for F, G being Function st F = the FacesAssign of T . n & G = F . f holds
S1 = G . x ) & ( for F, G being Function st F = the FacesAssign of T . n & G = F . f holds
S2 = G . x ) implies S1 = S2 )
assume that
A7:
for F, G being Function st F = the FacesAssign of T . n & G = F . f holds
S1 = G . x
and
A8:
for F, G being Function st F = the FacesAssign of T . n & G = F . f holds
S2 = G . x
; S1 = S2
reconsider F = the FacesAssign of T . n9 as Function of (NatEmbSeq . n9),((FuncsSeq the SkeletonSeq of T) . n9) by PBOOLE:def 15;
F . f in (FuncsSeq the SkeletonSeq of T) . n9
by FUNCT_2:5;
then
F . f in Funcs (( the SkeletonSeq of T . (n + 1)),( the SkeletonSeq of T . n))
by Def3;
then consider G being Function such that
A9:
G = F . f
and
dom G = the SkeletonSeq of T . (n + 1)
and
rng G c= the SkeletonSeq of T . n
by FUNCT_2:def 2;
S1 = G . x
by A7, A9;
hence
S1 = S2
by A8, A9; verum