Theorem nfdisjw 5079

Description: Bound-variable hypothesis builder for disjoint collection. Version of nfdisj 5080 with a disjoint variable condition, which does not require ax-13 2403. (Contributed by Mario Carneiro, 14-Nov-2016.) Avoid ax-13 2403. (Revised by GG, 26-Jan-2024.)

Hypotheses

Ref	Expression
nfdisjw.1	⊢ Ⅎ𝑦𝐴
nfdisjw.2	⊢ Ⅎ𝑦𝐵

Assertion

Ref	Expression
nfdisjw	⊢ Ⅎ𝑦Disj 𝑥 ∈ 𝐴 𝐵

Distinct variable group:   𝑥,𝑦

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

Proof of Theorem nfdisjw

Dummy variable 𝑧 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		dfdisj2 5069	. 2 ⊢ (Disj 𝑥 ∈ 𝐴 𝐵 ↔ ∀𝑧∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐵))
2		nftru 1824	. . . . 5 ⊢ Ⅎ𝑥⊤
3		nfdisjw.1	. . . . . . . 8 ⊢ Ⅎ𝑦𝐴
4	3	a1i 11	. . . . . . 7 ⊢ (⊤ → Ⅎ𝑦𝐴)
5	4	nfcrd 2918	. . . . . 6 ⊢ (⊤ → Ⅎ𝑦 𝑥 ∈ 𝐴)
6		nfdisjw.2	. . . . . . . 8 ⊢ Ⅎ𝑦𝐵
7	6	nfcri 2916	. . . . . . 7 ⊢ Ⅎ𝑦 𝑧 ∈ 𝐵
8	7	a1i 11	. . . . . 6 ⊢ (⊤ → Ⅎ𝑦 𝑧 ∈ 𝐵)
9	5, 8	nfand 1917	. . . . 5 ⊢ (⊤ → Ⅎ𝑦(𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐵))
10	2, 9	nfmodv 2586	. . . 4 ⊢ (⊤ → Ⅎ𝑦∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐵))
11	10	mptru 1567	. . 3 ⊢ Ⅎ𝑦∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐵)
12	11	nfal 2355	. 2 ⊢ Ⅎ𝑦∀𝑧∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑧 ∈ 𝐵)
13	1, 12	nfxfr 1873	1 ⊢ Ⅎ𝑦Disj 𝑥 ∈ 𝐴 𝐵

Syntax hints:   ∧ wa 399  ∀wal 1558  ⊤wtru 1561  Ⅎwnf 1803   ∈ wcel 2142  ∃*wmo 2564  Ⅎwnfc 2909  Disj wdisj 5067

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1815  ax-4 1829  ax-5 1930  ax-6 1987  ax-7 2028  ax-8 2144  ax-10 2175  ax-11 2191  ax-12 2212

This theorem depends on definitions:  df-bi 209  df-an 400  df-or 859  df-tru 1563  df-ex 1800  df-nf 1804  df-mo 2566  df-clel 2837  df-nfc 2911  df-rmo 3367  df-disj 5068

This theorem is referenced by:  disjxiun  5097