Metamath Proof Explorer


Theorem nfrmowOLD

Description: Obsolete version of nfrmow as of 21-Nov-2024. (Contributed by NM, 16-Jun-2017) (Revised by Gino Giotto, 10-Jan-2024) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses nfreuw.1
|- F/_ x A
nfreuw.2
|- F/ x ph
Assertion nfrmowOLD
|- F/ x E* y e. A ph

Proof

Step Hyp Ref Expression
1 nfreuw.1
 |-  F/_ x A
2 nfreuw.2
 |-  F/ x ph
3 df-rmo
 |-  ( E* y e. A ph <-> E* y ( y e. A /\ ph ) )
4 nftru
 |-  F/ y T.
5 nfcvd
 |-  ( T. -> F/_ x y )
6 1 a1i
 |-  ( T. -> F/_ x A )
7 5 6 nfeld
 |-  ( T. -> F/ x y e. A )
8 2 a1i
 |-  ( T. -> F/ x ph )
9 7 8 nfand
 |-  ( T. -> F/ x ( y e. A /\ ph ) )
10 4 9 nfmodv
 |-  ( T. -> F/ x E* y ( y e. A /\ ph ) )
11 10 mptru
 |-  F/ x E* y ( y e. A /\ ph )
12 3 11 nfxfr
 |-  F/ x E* y e. A ph