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Theorem nf3an 1474
Description: If  x is not free in  ph,  ps, and  ch, it is not free in  ( ph  /\  ps  /\  ch ). (Contributed by Mario Carneiro, 11-Aug-2016.)
Hypotheses
Ref Expression
nfan.1  |-  F/ x ph
nfan.2  |-  F/ x ps
nfan.3  |-  F/ x ch
Assertion
Ref Expression
nf3an  |-  F/ x
( ph  /\  ps  /\  ch )

Proof of Theorem nf3an
StepHypRef Expression
1 df-3an 898 . 2  |-  ( (
ph  /\  ps  /\  ch ) 
<->  ( ( ph  /\  ps )  /\  ch )
)
2 nfan.1 . . . 4  |-  F/ x ph
3 nfan.2 . . . 4  |-  F/ x ps
42, 3nfan 1473 . . 3  |-  F/ x
( ph  /\  ps )
5 nfan.3 . . 3  |-  F/ x ch
64, 5nfan 1473 . 2  |-  F/ x
( ( ph  /\  ps )  /\  ch )
71, 6nfxfr 1379 1  |-  F/ x
( ph  /\  ps  /\  ch )
Colors of variables: wff set class
Syntax hints:    /\ wa 101    /\ w3a 896   F/wnf 1365
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-5 1352  ax-gen 1354  ax-4 1416
This theorem depends on definitions:  df-bi 114  df-3an 898  df-nf 1366
This theorem is referenced by:  vtocl3gaf  2639  mob  2746  nfop  3593
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