Theorem bdcun 13375

Description: The union of two bounded classes is bounded. (Contributed by BJ, 3-Oct-2019.)

Hypotheses

Ref	Expression
bdcdif.1	⊢ BOUNDED 𝐴
bdcdif.2	⊢ BOUNDED 𝐵

Assertion

Ref	Expression
bdcun	⊢ BOUNDED (𝐴 ∪ 𝐵)

Proof of Theorem bdcun

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		bdcdif.1	. . . . 5 ⊢ BOUNDED 𝐴
2	1	bdeli 13359	. . . 4 ⊢ BOUNDED 𝑥 ∈ 𝐴
3		bdcdif.2	. . . . 5 ⊢ BOUNDED 𝐵
4	3	bdeli 13359	. . . 4 ⊢ BOUNDED 𝑥 ∈ 𝐵
5	2, 4	ax-bdor 13329	. . 3 ⊢ BOUNDED (𝑥 ∈ 𝐴 ∨ 𝑥 ∈ 𝐵)
6	5	bdcab 13362	. 2 ⊢ BOUNDED {𝑥 ∣ (𝑥 ∈ 𝐴 ∨ 𝑥 ∈ 𝐵)}
7		df-un 3102	. 2 ⊢ (𝐴 ∪ 𝐵) = {𝑥 ∣ (𝑥 ∈ 𝐴 ∨ 𝑥 ∈ 𝐵)}
8	6, 7	bdceqir 13357	1 ⊢ BOUNDED (𝐴 ∪ 𝐵)

Syntax hints:   ∨ wo 698   ∈ wcel 2125  {cab 2140   ∪ cun 3096  BOUNDED wbdc 13353

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1424  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-4 1487  ax-17 1503  ax-ial 1511  ax-ext 2136  ax-bd0 13326  ax-bdor 13329  ax-bdsb 13335

This theorem depends on definitions:  df-bi 116  df-clab 2141  df-cleq 2147  df-clel 2150  df-un 3102  df-bdc 13354

This theorem is referenced by:  bdcpr  13384  bdctp  13385  bdcsuc  13393