Theorem uneq1d 1610

Description: Deduction adding union to the right in a class equality.

Hypothesis

Ref	Expression
uneq1d.1	⊢ (φ → A = B)

Assertion

Ref	Expression
uneq1d	⊢ (φ → (A ∪ C) = (B ∪ C))

Proof of Theorem uneq1d

Step	Hyp	Ref	Expression
1		uneq1d.1	. 2 ⊢ (φ → A = B)
2		uneq1 1605	. 2 ⊢ (A = B → (A ∪ C) = (B ∪ C))
3	1, 2	syl 12	1 ⊢ (φ → (A ∪ C) = (B ∪ C))

Syntax hints:   → wi 2   = wceq 1091   ∪ cun 1485

This theorem is referenced by:  uneq12d 1612  preq1 1870  sbthlem5 3353  mapunen 3397  fodomb 3615  cdavalt 3716

This theorem was proved from axioms:  ax-1 3  ax-2 4  ax-3 5  ax-mp 6  ax-4 673  ax-5 674  ax-6 675  ax-7 676  ax-gen 677  ax-8 798  ax-9 799  ax-10 800  ax-11 801  ax-12 802  ax-16 922  ax-17 925  ax-ext 1074

This theorem depends on definitions:  df-bi 128  df-or 197  df-an 198  df-ex 679  df-sb 853  df-clab 1093  df-cleq 1097  df-clel 1099  df-v 1349  df-un 1490

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