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