Theorem sbcabel 3824

Description: Interchange class substitution and class abstraction. (Contributed by NM, 5-Nov-2005.)

Hypothesis

Ref	Expression
sbcabel.1	⊢ Ⅎ𝑥𝐵

Assertion

Ref	Expression
sbcabel	⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]{𝑦 ∣ 𝜑} ∈ 𝐵 ↔ {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∈ 𝐵))

Distinct variable groups:   𝑦,𝐴   𝑥,𝑦

Allowed substitution hints:   𝜑(𝑥, 𝑦)   𝐴(𝑥)   𝐵(𝑥, 𝑦)   𝑉(𝑥, 𝑦)

Proof of Theorem sbcabel

Dummy variable 𝑤 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		elex 3471	. 2 ⊢ (𝐴 ∈ 𝑉 → 𝐴 ∈ V)
2		sbcex2 3798	. . . 4 ⊢ ([𝐴 / 𝑥]∃𝑤(𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵) ↔ ∃𝑤[𝐴 / 𝑥](𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵))
3		sbcan 3787	. . . . . 6 ⊢ ([𝐴 / 𝑥](𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵) ↔ ([𝐴 / 𝑥]𝑤 = {𝑦 ∣ 𝜑} ∧ [𝐴 / 𝑥]𝑤 ∈ 𝐵))
4		sbcal 3797	. . . . . . . . 9 ⊢ ([𝐴 / 𝑥]∀𝑦(𝑦 ∈ 𝑤 ↔ 𝜑) ↔ ∀𝑦[𝐴 / 𝑥](𝑦 ∈ 𝑤 ↔ 𝜑))
5		sbcbig 3789	. . . . . . . . . . 11 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥](𝑦 ∈ 𝑤 ↔ 𝜑) ↔ ([𝐴 / 𝑥]𝑦 ∈ 𝑤 ↔ [𝐴 / 𝑥]𝜑)))
6		sbcg 3810	. . . . . . . . . . . 12 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥]𝑦 ∈ 𝑤 ↔ 𝑦 ∈ 𝑤))
7	6	bibi1d 346	. . . . . . . . . . 11 ⊢ (𝐴 ∈ V → (([𝐴 / 𝑥]𝑦 ∈ 𝑤 ↔ [𝐴 / 𝑥]𝜑) ↔ (𝑦 ∈ 𝑤 ↔ [𝐴 / 𝑥]𝜑)))
8	5, 7	bitrd 282	. . . . . . . . . 10 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥](𝑦 ∈ 𝑤 ↔ 𝜑) ↔ (𝑦 ∈ 𝑤 ↔ [𝐴 / 𝑥]𝜑)))
9	8	albidv 1953	. . . . . . . . 9 ⊢ (𝐴 ∈ V → (∀𝑦[𝐴 / 𝑥](𝑦 ∈ 𝑤 ↔ 𝜑) ↔ ∀𝑦(𝑦 ∈ 𝑤 ↔ [𝐴 / 𝑥]𝜑)))
10	4, 9	bitrid 286	. . . . . . . 8 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥]∀𝑦(𝑦 ∈ 𝑤 ↔ 𝜑) ↔ ∀𝑦(𝑦 ∈ 𝑤 ↔ [𝐴 / 𝑥]𝜑)))
11		eqabb 2899	. . . . . . . . 9 ⊢ (𝑤 = {𝑦 ∣ 𝜑} ↔ ∀𝑦(𝑦 ∈ 𝑤 ↔ 𝜑))
12	11	sbcbii 3794	. . . . . . . 8 ⊢ ([𝐴 / 𝑥]𝑤 = {𝑦 ∣ 𝜑} ↔ [𝐴 / 𝑥]∀𝑦(𝑦 ∈ 𝑤 ↔ 𝜑))
13		eqabb 2899	. . . . . . . 8 ⊢ (𝑤 = {𝑦 ∣ [𝐴 / 𝑥]𝜑} ↔ ∀𝑦(𝑦 ∈ 𝑤 ↔ [𝐴 / 𝑥]𝜑))
14	10, 12, 13	3bitr4g 317	. . . . . . 7 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥]𝑤 = {𝑦 ∣ 𝜑} ↔ 𝑤 = {𝑦 ∣ [𝐴 / 𝑥]𝜑}))
15		sbcabel.1	. . . . . . . . 9 ⊢ Ⅎ𝑥𝐵
16	15	nfcri 2914	. . . . . . . 8 ⊢ Ⅎ𝑥 𝑤 ∈ 𝐵
17	16	sbcgf 3808	. . . . . . 7 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥]𝑤 ∈ 𝐵 ↔ 𝑤 ∈ 𝐵))
18	14, 17	anbi12d 644	. . . . . 6 ⊢ (𝐴 ∈ V → (([𝐴 / 𝑥]𝑤 = {𝑦 ∣ 𝜑} ∧ [𝐴 / 𝑥]𝑤 ∈ 𝐵) ↔ (𝑤 = {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∧ 𝑤 ∈ 𝐵)))
19	3, 18	bitrid 286	. . . . 5 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥](𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵) ↔ (𝑤 = {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∧ 𝑤 ∈ 𝐵)))
20	19	exbidv 1954	. . . 4 ⊢ (𝐴 ∈ V → (∃𝑤[𝐴 / 𝑥](𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵) ↔ ∃𝑤(𝑤 = {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∧ 𝑤 ∈ 𝐵)))
21	2, 20	bitrid 286	. . 3 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥]∃𝑤(𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵) ↔ ∃𝑤(𝑤 = {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∧ 𝑤 ∈ 𝐵)))
22		dfclel 2836	. . . 4 ⊢ ({𝑦 ∣ 𝜑} ∈ 𝐵 ↔ ∃𝑤(𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵))
23	22	sbcbii 3794	. . 3 ⊢ ([𝐴 / 𝑥]{𝑦 ∣ 𝜑} ∈ 𝐵 ↔ [𝐴 / 𝑥]∃𝑤(𝑤 = {𝑦 ∣ 𝜑} ∧ 𝑤 ∈ 𝐵))
24		dfclel 2836	. . 3 ⊢ ({𝑦 ∣ [𝐴 / 𝑥]𝜑} ∈ 𝐵 ↔ ∃𝑤(𝑤 = {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∧ 𝑤 ∈ 𝐵))
25	21, 23, 24	3bitr4g 317	. 2 ⊢ (𝐴 ∈ V → ([𝐴 / 𝑥]{𝑦 ∣ 𝜑} ∈ 𝐵 ↔ {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∈ 𝐵))
26	1, 25	syl 18	1 ⊢ (𝐴 ∈ 𝑉 → ([𝐴 / 𝑥]{𝑦 ∣ 𝜑} ∈ 𝐵 ↔ {𝑦 ∣ [𝐴 / 𝑥]𝜑} ∈ 𝐵))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401  ∀wal 1568   = wceq 1570  ∃wex 1812   ∈ wcel 2145  {cab 2738  Ⅎwnfc 2907  Vcvv 3450  [wsbc 3738

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-11 2194  ax-12 2213  ax-ext 2732

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-tru 1573  df-ex 1813  df-nf 1817  df-sb 2100  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-v 3452  df-sbc 3739

This theorem is used by:  csbexg  5263