Theorem nfvd 1509

Description: nfv 1508 with antecedent. Useful in proofs of deduction versions of bound-variable hypothesis builders such as nfimd 1564. (Contributed by Mario Carneiro, 6-Oct-2016.)

Assertion

Ref	Expression
nfvd	⊢ (𝜑 → Ⅎ𝑥𝜓)

Distinct variable group:   𝜓,𝑥

Allowed substitution hint:   𝜑(𝑥)

Proof of Theorem nfvd

Step	Hyp	Ref	Expression
1		nfv 1508	. 2 ⊢ Ⅎ𝑥𝜓
2	1	a1i 9	1 ⊢ (𝜑 → Ⅎ𝑥𝜓)

Syntax hints:   → wi 4  Ⅎwnf 1436

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-gen 1425  ax-17 1506

This theorem depends on definitions:  df-bi 116  df-nf 1437

This theorem is referenced by:  sbiedv  1762  cbvaldva  1900  cbvexdva  1901  vtocld  2738  sbcied  2945  nfunid  3743  peano2  4509  iota2d  5113  iota2  5114  riota5f  5754  mpoxopoveq  6137  bdsepnft  13085  strcollnft  13182