Metamath Proof Explorer


Theorem nf3and

Description: Deduction form of bound-variable hypothesis builder nf3an . (Contributed by NM, 17-Feb-2013) (Revised by Mario Carneiro, 16-Oct-2016)

Ref Expression
Hypotheses nfand.1
|- ( ph -> F/ x ps )
nfand.2
|- ( ph -> F/ x ch )
nfand.3
|- ( ph -> F/ x th )
Assertion nf3and
|- ( ph -> F/ x ( ps /\ ch /\ th ) )

Proof

Step Hyp Ref Expression
1 nfand.1
 |-  ( ph -> F/ x ps )
2 nfand.2
 |-  ( ph -> F/ x ch )
3 nfand.3
 |-  ( ph -> F/ x th )
4 df-3an
 |-  ( ( ps /\ ch /\ th ) <-> ( ( ps /\ ch ) /\ th ) )
5 1 2 nfand
 |-  ( ph -> F/ x ( ps /\ ch ) )
6 5 3 nfand
 |-  ( ph -> F/ x ( ( ps /\ ch ) /\ th ) )
7 4 6 nfxfrd
 |-  ( ph -> F/ x ( ps /\ ch /\ th ) )