let D be non empty set ; for F being PartFunc of D,REAL
for X being set
for r being Real
for Z being finite set st Z = dom (F | X) & rng (F | X) = {r} holds
FinS F,X = (card Z) |-> r
let F be PartFunc of D,REAL ; for X being set
for r being Real
for Z being finite set st Z = dom (F | X) & rng (F | X) = {r} holds
FinS F,X = (card Z) |-> r
let X be set ; for r being Real
for Z being finite set st Z = dom (F | X) & rng (F | X) = {r} holds
FinS F,X = (card Z) |-> r
let r be Real; for Z being finite set st Z = dom (F | X) & rng (F | X) = {r} holds
FinS F,X = (card Z) |-> r
let dx be finite set ; ( dx = dom (F | X) & rng (F | X) = {r} implies FinS F,X = (card dx) |-> r )
assume A1:
dx = dom (F | X)
; ( not rng (F | X) = {r} or FinS F,X = (card dx) |-> r )
set fx = FinS F,X;
assume A2:
rng (F | X) = {r}
; FinS F,X = (card dx) |-> r
F | X, FinS F,X are_fiberwise_equipotent
by A1, Def14;
then A3:
rng (FinS F,X) = {r}
by A2, CLASSES1:83;
A4:
dom (FinS F,X) = Seg (len (FinS F,X))
by FINSEQ_1:def 3;
len (FinS F,X) = card dx
by A1, Th70;
hence
FinS F,X = (card dx) |-> r
by A3, A4, FUNCOP_1:15; verum