Metamath Proof Explorer


Theorem fin23lem16

Description: Lemma for fin23 . U ranges over the original set; in particular ran U is a set, although we do not assume here that U is. (Contributed by Stefan O'Rear, 1-Nov-2014)

Ref Expression
Hypothesis fin23lem.a U = seq ω i ω , u V if t i u = u t i u ran t
Assertion fin23lem16 ran U = ran t

Proof

Step Hyp Ref Expression
1 fin23lem.a U = seq ω i ω , u V if t i u = u t i u ran t
2 unissb ran U ran t a ran U a ran t
3 1 fnseqom U Fn ω
4 fvelrnb U Fn ω a ran U b ω U b = a
5 3 4 ax-mp a ran U b ω U b = a
6 peano1 ω
7 0ss b
8 1 fin23lem15 b ω ω b U b U
9 7 8 mpan2 b ω ω U b U
10 6 9 mpan2 b ω U b U
11 vex t V
12 11 rnex ran t V
13 12 uniex ran t V
14 1 seqom0g ran t V U = ran t
15 13 14 ax-mp U = ran t
16 10 15 sseqtrdi b ω U b ran t
17 sseq1 U b = a U b ran t a ran t
18 16 17 syl5ibcom b ω U b = a a ran t
19 18 rexlimiv b ω U b = a a ran t
20 5 19 sylbi a ran U a ran t
21 2 20 mprgbir ran U ran t
22 fnfvelrn U Fn ω ω U ran U
23 3 6 22 mp2an U ran U
24 15 23 eqeltrri ran t ran U
25 elssuni ran t ran U ran t ran U
26 24 25 ax-mp ran t ran U
27 21 26 eqssi ran U = ran t