let D be non empty set ; for F being PartFunc of D,REAL
for X being set st dom (F | X) is finite holds
FinS ((F | X),X) = FinS (F,X)
let F be PartFunc of D,REAL; for X being set st dom (F | X) is finite holds
FinS ((F | X),X) = FinS (F,X)
let X be set ; ( dom (F | X) is finite implies FinS ((F | X),X) = FinS (F,X) )
A1:
(F | X) | X = F | X
by RELAT_1:72;
assume A2:
dom (F | X) is finite
; FinS ((F | X),X) = FinS (F,X)
then
FinS (F,X),F | X are_fiberwise_equipotent
by Def13;
hence
FinS ((F | X),X) = FinS (F,X)
by A2, A1, Def13; verum