Theorem erbr3b 32279

Description: Biconditional for equivalent elements. (Contributed by Thierry Arnoux, 6-Jan-2020.)

Assertion

Ref	Expression
erbr3b	⊢ ((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) → (𝐴𝑅𝐶 ↔ 𝐵𝑅𝐶))

Proof of Theorem erbr3b

Step	Hyp	Ref	Expression
1		simpll 764	. . 3 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐴𝑅𝐶) → 𝑅 Er 𝑋)
2		simplr 766	. . 3 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐴𝑅𝐶) → 𝐴𝑅𝐵)
3		simpr 484	. . 3 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐴𝑅𝐶) → 𝐴𝑅𝐶)
4	1, 2, 3	ertr3d 8727	. 2 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐴𝑅𝐶) → 𝐵𝑅𝐶)
5		simpll 764	. . 3 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐵𝑅𝐶) → 𝑅 Er 𝑋)
6		simplr 766	. . 3 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐵𝑅𝐶) → 𝐴𝑅𝐵)
7		simpr 484	. . 3 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐵𝑅𝐶) → 𝐵𝑅𝐶)
8	5, 6, 7	ertrd 8725	. 2 ⊢ (((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) ∧ 𝐵𝑅𝐶) → 𝐴𝑅𝐶)
9	4, 8	impbida 798	1 ⊢ ((𝑅 Er 𝑋 ∧ 𝐴𝑅𝐵) → (𝐴𝑅𝐶 ↔ 𝐵𝑅𝐶))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 395   class class class wbr 5148   Er wer 8706

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1912  ax-6 1970  ax-7 2010  ax-8 2107  ax-9 2115  ax-ext 2702  ax-sep 5299  ax-nul 5306  ax-pr 5427

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 845  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1781  df-sb 2067  df-clab 2709  df-cleq 2723  df-clel 2809  df-ral 3061  df-rex 3070  df-rab 3432  df-v 3475  df-dif 3951  df-un 3953  df-in 3955  df-ss 3965  df-nul 4323  df-if 4529  df-sn 4629  df-pr 4631  df-op 4635  df-br 5149  df-opab 5211  df-xp 5682  df-rel 5683  df-cnv 5684  df-co 5685  df-er 8709

This theorem is referenced by: (None)