Theorem breq2dd 5128

Description: Equality deduction for a binary relation. (Contributed by Thierry Arnoux, 10-Jan-2026.)

Hypotheses

Ref	Expression
breq2dd.1	⊢ (𝜑 → 𝐴 = 𝐵)
breq2dd.2	⊢ (𝜑 → 𝐶𝑅𝐴)

Assertion

Ref	Expression
breq2dd	⊢ (𝜑 → 𝐶𝑅𝐵)

Proof of Theorem breq2dd

Step	Hyp	Ref	Expression
1		breq2dd.2	. 2 ⊢ (𝜑 → 𝐶𝑅𝐴)
2		breq2dd.1	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
3	2	breq2d 5121	. 2 ⊢ (𝜑 → (𝐶𝑅𝐴 ↔ 𝐶𝑅𝐵))
4	1, 3	mpbid 235	1 ⊢ (𝜑 → 𝐶𝑅𝐵)

Syntax hints:   → wi 4   = wceq 1570   class class class wbr 5109

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1825  ax-4 1839  ax-5 1940  ax-6 1997  ax-7 2038  ax-8 2145  ax-9 2153  ax-ext 2735

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1810  df-sb 2097  df-clab 2742  df-cleq 2755  df-clel 2838  df-rab 3417  df-v 3457  df-dif 3908  df-un 3910  df-ss 3922  df-nul 4287  df-if 4488  df-sn 4590  df-pr 4592  df-op 4596  df-br 5110

This theorem is referenced by:  prlngmid2  29211