let D be non empty set ; for f being FinSequence
for d being Element of D holds d is_common_for_dom CHI f,D
let f be FinSequence; for d being Element of D holds d is_common_for_dom CHI f,D
let d be Element of D; d is_common_for_dom CHI f,D
let G be Element of PFuncs D,REAL ; RFUNCT_3:def 9 for n being Element of NAT st n in dom (CHI f,D) & (CHI f,D) . n = G holds
d in dom G
let n be Element of NAT ; ( n in dom (CHI f,D) & (CHI f,D) . n = G implies d in dom G )
assume
( n in dom (CHI f,D) & (CHI f,D) . n = G )
; d in dom G
then
G = chi (f . n),D
by Def6;
then
dom G = D
by RFUNCT_1:77;
hence
d in dom G
; verum