Metamath Proof Explorer


Theorem tz9.12lem2

Description: Lemma for tz9.12 . (Contributed by NM, 22-Sep-2003)

Ref Expression
Hypotheses tz9.12lem.1
|- A e. _V
tz9.12lem.2
|- F = ( z e. _V |-> |^| { v e. On | z e. ( R1 ` v ) } )
Assertion tz9.12lem2
|- suc U. ( F " A ) e. On

Proof

Step Hyp Ref Expression
1 tz9.12lem.1
 |-  A e. _V
2 tz9.12lem.2
 |-  F = ( z e. _V |-> |^| { v e. On | z e. ( R1 ` v ) } )
3 1 2 tz9.12lem1
 |-  ( F " A ) C_ On
4 2 funmpt2
 |-  Fun F
5 1 funimaex
 |-  ( Fun F -> ( F " A ) e. _V )
6 4 5 ax-mp
 |-  ( F " A ) e. _V
7 6 ssonunii
 |-  ( ( F " A ) C_ On -> U. ( F " A ) e. On )
8 3 7 ax-mp
 |-  U. ( F " A ) e. On
9 8 onsuci
 |-  suc U. ( F " A ) e. On