Theorem sbied 1671

Description: Conversion of implicit substitution to explicit substitution (deduction version of sbie 1674). (Contributed by NM, 30-Jun-1994.) (Revised by Mario Carneiro, 4-Oct-2016.)

Hypotheses

Ref	Expression
sbied.1	⊢ Ⅎ𝑥𝜑
sbied.2	⊢ (𝜑 → Ⅎ𝑥𝜒)
sbied.3	⊢ (𝜑 → (𝑥 = 𝑦 → (𝜓 ↔ 𝜒)))

Assertion

Ref	Expression
sbied	⊢ (𝜑 → ([𝑦 / 𝑥]𝜓 ↔ 𝜒))

Proof of Theorem sbied

Step	Hyp	Ref	Expression
1		sbied.1	. . 3 ⊢ Ⅎ𝑥𝜑
2	1	nfri 1412	. 2 ⊢ (𝜑 → ∀𝑥𝜑)
3		sbied.2	. . 3 ⊢ (𝜑 → Ⅎ𝑥𝜒)
4	3	nfrd 1413	. 2 ⊢ (𝜑 → (𝜒 → ∀𝑥𝜒))
5		sbied.3	. 2 ⊢ (𝜑 → (𝑥 = 𝑦 → (𝜓 ↔ 𝜒)))
6	2, 4, 5	sbiedh 1670	1 ⊢ (𝜑 → ([𝑦 / 𝑥]𝜓 ↔ 𝜒))

Syntax hints:   → wi 4   ↔ wb 98  Ⅎwnf 1349  [wsb 1645

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-5 1336  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-4 1400  ax-i9 1423  ax-ial 1427

This theorem depends on definitions:  df-bi 110  df-nf 1350  df-sb 1646

This theorem is referenced by:  sbiedv  1672  dvelimdf  1892  cbvrald  9927