Metamath Proof Explorer


Theorem eqvrelcoss2

Description: Two ways to express equivalent cosets. (Contributed by Peter Mazsa, 3-May-2019)

Ref Expression
Assertion eqvrelcoss2 ( EqvRel ≀ 𝑅 ↔ ≀ ≀ 𝑅 ⊆ ≀ 𝑅 )

Proof

Step Hyp Ref Expression
1 eqvrelcoss3 ( EqvRel ≀ 𝑅 ↔ ∀ 𝑥𝑦𝑧 ( ( 𝑥𝑅 𝑦𝑦𝑅 𝑧 ) → 𝑥𝑅 𝑧 ) )
2 cocossss ( ≀ ≀ 𝑅 ⊆ ≀ 𝑅 ↔ ∀ 𝑥𝑦𝑧 ( ( 𝑥𝑅 𝑦𝑦𝑅 𝑧 ) → 𝑥𝑅 𝑧 ) )
3 1 2 bitr4i ( EqvRel ≀ 𝑅 ↔ ≀ ≀ 𝑅 ⊆ ≀ 𝑅 )