Theorem uneq1i 3277

Description: Inference adding union to the right in a class equality. (Contributed by NM, 30-Aug-1993.)

Hypothesis

Ref	Expression
uneq1i.1	⊢ 𝐴 = 𝐵

Assertion

Ref	Expression
uneq1i	⊢ (𝐴 ∪ 𝐶) = (𝐵 ∪ 𝐶)

Proof of Theorem uneq1i

Step	Hyp	Ref	Expression
1		uneq1i.1	. 2 ⊢ 𝐴 = 𝐵
2		uneq1 3274	. 2 ⊢ (𝐴 = 𝐵 → (𝐴 ∪ 𝐶) = (𝐵 ∪ 𝐶))
3	1, 2	ax-mp 5	1 ⊢ (𝐴 ∪ 𝐶) = (𝐵 ∪ 𝐶)

Syntax hints:   = wceq 1348   ∪ cun 3119

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-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152

This theorem depends on definitions:  df-bi 116  df-tru 1351  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-v 2732  df-un 3125

This theorem is referenced by:  un12  3285  unundi  3288  tpcoma  3677  qdass  3680  qdassr  3681  tpidm12  3682  resasplitss  5377  fmptpr  5688  df2o3  6409  undifdc  6901  sbthlemi6  6939  exmidfodomrlemim  7178  znnen  12353  setscom  12456