Theorem ertr3d 8722

Description: A transitivity relation for equivalences. (Contributed by Mario Carneiro, 9-Jul-2014.)

Hypotheses

Ref	Expression
ersymb.1	⊢ (𝜑 → 𝑅 Er 𝑋)
ertr3d.5	⊢ (𝜑 → 𝐵𝑅𝐴)
ertr3d.6	⊢ (𝜑 → 𝐵𝑅𝐶)

Assertion

Ref	Expression
ertr3d	⊢ (𝜑 → 𝐴𝑅𝐶)

Proof of Theorem ertr3d

Step	Hyp	Ref	Expression
1		ersymb.1	. 2 ⊢ (𝜑 → 𝑅 Er 𝑋)
2		ertr3d.5	. . 3 ⊢ (𝜑 → 𝐵𝑅𝐴)
3	1, 2	ersym 8716	. 2 ⊢ (𝜑 → 𝐴𝑅𝐵)
4		ertr3d.6	. 2 ⊢ (𝜑 → 𝐵𝑅𝐶)
5	1, 3, 4	ertrd 8720	1 ⊢ (𝜑 → 𝐴𝑅𝐶)

This proof depends on syntax axioms:   → wi 4   class class class wbr 5114   Er wer 8700

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2148  ax-9 2156  ax-ext 2738  ax-sep 5262  ax-pr 5409

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-sb 2100  df-clab 2745  df-cleq 2758  df-clel 2841  df-ral 3083  df-rex 3093  df-rab 3420  df-v 3460  df-dif 3911  df-un 3913  df-in 3915  df-ss 3925  df-nul 4290  df-if 4493  df-sn 4595  df-pr 4597  df-op 4601  df-br 5115  df-opab 5179  df-xp 5672  df-rel 5673  df-cnv 5674  df-co 5675  df-er 8703

This theorem is used by:  nqereq  10938  efgred2  19854  xmetresbl  24631  pcophtb  25225  pi1xfr  25251  pi1xfrcnvlem  25252  erbr3b  32999  prtlem10  39680