Theorem bdvsn 16900

Description: Equality of a setvar with a singleton of a setvar is a bounded formula. (Contributed by BJ, 16-Oct-2019.)

Assertion

Ref	Expression
bdvsn	⊢ BOUNDED 𝑥 = {𝑦}

Distinct variable group:   𝑥,𝑦

Proof of Theorem bdvsn

Step	Hyp	Ref	Expression
1		bdcsn 16896	. . . 4 ⊢ BOUNDED {𝑦}
2	1	bdss 16890	. . 3 ⊢ BOUNDED 𝑥 ⊆ {𝑦}
3		bdcv 16874	. . . 4 ⊢ BOUNDED 𝑥
4	3	bdsnss 16899	. . 3 ⊢ BOUNDED {𝑦} ⊆ 𝑥
5	2, 4	ax-bdan 16841	. 2 ⊢ BOUNDED (𝑥 ⊆ {𝑦} ∧ {𝑦} ⊆ 𝑥)
6		eqss 3263	. 2 ⊢ (𝑥 = {𝑦} ↔ (𝑥 ⊆ {𝑦} ∧ {𝑦} ⊆ 𝑥))
7	5, 6	bd0r 16851	1 ⊢ BOUNDED 𝑥 = {𝑦}

This proof depends on syntax axioms:   ∧ wa 104   = wceq 1402   ⊆ wss 3220  {csn 3709  BOUNDED wbd 16838

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220  ax-bd0 16839  ax-bdan 16841  ax-bdal 16844  ax-bdeq 16846  ax-bdel 16847  ax-bdsb 16848

This proof depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ral 2533  df-v 2823  df-in 3226  df-ss 3233  df-sn 3715  df-bdc 16867

This theorem is used by:  bdop  16901