Theorem elabgft1 14615

Description: One implication of elabgf 2881, in closed form. (Contributed by BJ, 21-Nov-2019.)

Hypotheses

Ref	Expression
elabgf1.nf1	⊢ Ⅎ𝑥𝐴
elabgf1.nf2	⊢ Ⅎ𝑥𝜓

Assertion

Ref	Expression
elabgft1	⊢ (∀𝑥(𝑥 = 𝐴 → (𝜑 → 𝜓)) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓))

Proof of Theorem elabgft1

Step	Hyp	Ref	Expression
1		biimp 118	. . . . . 6 ⊢ ((𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜑))
2		imim2 55	. . . . . 6 ⊢ ((𝜑 → 𝜓) → ((𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜑) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓)))
3	1, 2	syl5 32	. . . . 5 ⊢ ((𝜑 → 𝜓) → ((𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓)))
4	3	imim2i 12	. . . 4 ⊢ ((𝑥 = 𝐴 → (𝜑 → 𝜓)) → (𝑥 = 𝐴 → ((𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓))))
5	4	alimi 1455	. . 3 ⊢ (∀𝑥(𝑥 = 𝐴 → (𝜑 → 𝜓)) → ∀𝑥(𝑥 = 𝐴 → ((𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓))))
6		elabgf1.nf1	. . . 4 ⊢ Ⅎ𝑥𝐴
7		nfab1 2321	. . . . . 6 ⊢ Ⅎ𝑥{𝑥 ∣ 𝜑}
8	6, 7	nfel 2328	. . . . 5 ⊢ Ⅎ𝑥 𝐴 ∈ {𝑥 ∣ 𝜑}
9		elabgf1.nf2	. . . . 5 ⊢ Ⅎ𝑥𝜓
10	8, 9	nfim 1572	. . . 4 ⊢ Ⅎ𝑥(𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓)
11		elabgf0 14614	. . . 4 ⊢ (𝑥 = 𝐴 → (𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑))
12	6, 10, 11	bj-vtoclgft 14612	. . 3 ⊢ (∀𝑥(𝑥 = 𝐴 → ((𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜑) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓))) → (𝐴 ∈ {𝑥 ∣ 𝜑} → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓)))
13	5, 12	syl 14	. 2 ⊢ (∀𝑥(𝑥 = 𝐴 → (𝜑 → 𝜓)) → (𝐴 ∈ {𝑥 ∣ 𝜑} → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓)))
14	13	pm2.43d 50	1 ⊢ (∀𝑥(𝑥 = 𝐴 → (𝜑 → 𝜓)) → (𝐴 ∈ {𝑥 ∣ 𝜑} → 𝜓))

Syntax hints:   → wi 4   ↔ wb 105  ∀wal 1351   = wceq 1353  Ⅎwnf 1460   ∈ wcel 2148  {cab 2163  Ⅎwnfc 2306

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159

This theorem depends on definitions:  df-bi 117  df-tru 1356  df-nf 1461  df-sb 1763  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-v 2741

This theorem is referenced by:  elabgf1  14616