Theorem rabtru 3705

Description: Abstract builder using the constant wff ⊤. (Contributed by Thierry Arnoux, 4-May-2020.)

Hypothesis

Ref	Expression
rabtru.1	⊢ Ⅎ𝑥𝐴

Assertion

Ref	Expression
rabtru	⊢ {𝑥 ∈ 𝐴 ∣ ⊤} = 𝐴

Proof of Theorem rabtru

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		tru 1541	. . 3 ⊢ ⊤
2		nfcv 2908	. . . 4 ⊢ Ⅎ𝑥𝑦
3		rabtru.1	. . . 4 ⊢ Ⅎ𝑥𝐴
4		nftru 1802	. . . 4 ⊢ Ⅎ𝑥⊤
5		biidd 262	. . . 4 ⊢ (𝑥 = 𝑦 → (⊤ ↔ ⊤))
6	2, 3, 4, 5	elrabf 3704	. . 3 ⊢ (𝑦 ∈ {𝑥 ∈ 𝐴 ∣ ⊤} ↔ (𝑦 ∈ 𝐴 ∧ ⊤))
7	1, 6	mpbiran2 709	. 2 ⊢ (𝑦 ∈ {𝑥 ∈ 𝐴 ∣ ⊤} ↔ 𝑦 ∈ 𝐴)
8	7	eqriv 2737	1 ⊢ {𝑥 ∈ 𝐴 ∣ ⊤} = 𝐴

Syntax hints:   = wceq 1537  ⊤wtru 1538   ∈ wcel 2108  Ⅎwnfc 2893  {crab 3443

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-10 2141  ax-11 2158  ax-12 2178  ax-ext 2711

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 847  df-tru 1540  df-ex 1778  df-nf 1782  df-sb 2065  df-clab 2718  df-cleq 2732  df-clel 2819  df-nfc 2895  df-rab 3444  df-v 3490

This theorem is referenced by:  mptexgf  7259  aciunf1  32681