Metamath Proof Explorer


Theorem ssltsepc

Description: Two elements of separated sets obey less than. (Contributed by Scott Fenton, 20-Aug-2024)

Ref Expression
Assertion ssltsepc ( ( 𝐴 <<s 𝐵𝑋𝐴𝑌𝐵 ) → 𝑋 <s 𝑌 )

Proof

Step Hyp Ref Expression
1 ssltsep ( 𝐴 <<s 𝐵 → ∀ 𝑥𝐴𝑦𝐵 𝑥 <s 𝑦 )
2 breq1 ( 𝑥 = 𝑋 → ( 𝑥 <s 𝑦𝑋 <s 𝑦 ) )
3 breq2 ( 𝑦 = 𝑌 → ( 𝑋 <s 𝑦𝑋 <s 𝑌 ) )
4 2 3 rspc2va ( ( ( 𝑋𝐴𝑌𝐵 ) ∧ ∀ 𝑥𝐴𝑦𝐵 𝑥 <s 𝑦 ) → 𝑋 <s 𝑌 )
5 4 ancoms ( ( ∀ 𝑥𝐴𝑦𝐵 𝑥 <s 𝑦 ∧ ( 𝑋𝐴𝑌𝐵 ) ) → 𝑋 <s 𝑌 )
6 1 5 sylan ( ( 𝐴 <<s 𝐵 ∧ ( 𝑋𝐴𝑌𝐵 ) ) → 𝑋 <s 𝑌 )
7 6 3impb ( ( 𝐴 <<s 𝐵𝑋𝐴𝑌𝐵 ) → 𝑋 <s 𝑌 )