Metamath Proof Explorer


Theorem chnrin2

Description: Distribution of chain class constructor over relation intersection. (Contributed by Ender Ting, 24-Jul-2026)

Ref Expression
Assertion chnrin2 ( ( 𝑅< ) Chain 𝐵 ) = ( ( 𝑅 Chain 𝐵 ) ∩ ( < Chain 𝐵 ) )

Proof

Step Hyp Ref Expression
1 chnrrin ( 𝑛 ∈ ( ( 𝑅< ) Chain 𝐵 ) → ( 𝑛 ∈ ( 𝑅 Chain 𝐵 ) ∧ 𝑛 ∈ ( < Chain 𝐵 ) ) )
2 chnrin ( ( 𝑛 ∈ ( 𝑅 Chain 𝐵 ) ∧ 𝑛 ∈ ( < Chain 𝐵 ) ) → 𝑛 ∈ ( ( 𝑅< ) Chain 𝐵 ) )
3 1 2 impbii ( 𝑛 ∈ ( ( 𝑅< ) Chain 𝐵 ) ↔ ( 𝑛 ∈ ( 𝑅 Chain 𝐵 ) ∧ 𝑛 ∈ ( < Chain 𝐵 ) ) )
4 elin ( 𝑛 ∈ ( ( 𝑅 Chain 𝐵 ) ∩ ( < Chain 𝐵 ) ) ↔ ( 𝑛 ∈ ( 𝑅 Chain 𝐵 ) ∧ 𝑛 ∈ ( < Chain 𝐵 ) ) )
5 3 4 bitr4i ( 𝑛 ∈ ( ( 𝑅< ) Chain 𝐵 ) ↔ 𝑛 ∈ ( ( 𝑅 Chain 𝐵 ) ∩ ( < Chain 𝐵 ) ) )
6 5 eqriv ( ( 𝑅< ) Chain 𝐵 ) = ( ( 𝑅 Chain 𝐵 ) ∩ ( < Chain 𝐵 ) )