Theorem ertr4d 8720

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

Hypotheses

Ref	Expression
ersymb.1	⊢ (𝜑 → 𝑅 Er 𝑋)
ertr4d.5	⊢ (𝜑 → 𝐴𝑅𝐵)
ertr4d.6	⊢ (𝜑 → 𝐶𝑅𝐵)

Assertion

Ref	Expression
ertr4d	⊢ (𝜑 → 𝐴𝑅𝐶)

Proof of Theorem ertr4d

Step	Hyp	Ref	Expression
1		ersymb.1	. 2 ⊢ (𝜑 → 𝑅 Er 𝑋)
2		ertr4d.5	. 2 ⊢ (𝜑 → 𝐴𝑅𝐵)
3		ertr4d.6	. . 3 ⊢ (𝜑 → 𝐶𝑅𝐵)
4	1, 3	ersym 8713	. 2 ⊢ (𝜑 → 𝐵𝑅𝐶)
5	1, 2, 4	ertrd 8717	1 ⊢ (𝜑 → 𝐴𝑅𝐶)

This proof depends on syntax axioms:   → wi 4   class class class wbr 5107   Er wer 8697

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 2147  ax-9 2155  ax-ext 2734  ax-sep 5255  ax-pr 5402

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 2741  df-cleq 2754  df-clel 2837  df-ral 3079  df-rex 3089  df-rab 3415  df-v 3455  df-dif 3905  df-un 3907  df-in 3909  df-ss 3919  df-nul 4283  df-if 4486  df-sn 4588  df-pr 4590  df-op 4594  df-br 5108  df-opab 5172  df-xp 5665  df-rel 5666  df-cnv 5667  df-co 5668  df-er 8700

This theorem is used by:  erref  8721  erdisj  8758  nqereu  10942  nqereq  10948  efgredeu  19885  pi1xfr  25289  pi1xfrcnvlem  25290  prjspner1  43480