Description: A directed set is a proset. (Contributed by Stefan O'Rear, 1-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | drsprs | ⊢ ( 𝐾 ∈ Dirset → 𝐾 ∈ Proset ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid | ⊢ ( Base ‘ 𝐾 ) = ( Base ‘ 𝐾 ) | |
2 | eqid | ⊢ ( le ‘ 𝐾 ) = ( le ‘ 𝐾 ) | |
3 | 1 2 | isdrs | ⊢ ( 𝐾 ∈ Dirset ↔ ( 𝐾 ∈ Proset ∧ ( Base ‘ 𝐾 ) ≠ ∅ ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐾 ) ∀ 𝑦 ∈ ( Base ‘ 𝐾 ) ∃ 𝑧 ∈ ( Base ‘ 𝐾 ) ( 𝑥 ( le ‘ 𝐾 ) 𝑧 ∧ 𝑦 ( le ‘ 𝐾 ) 𝑧 ) ) ) |
4 | 3 | simp1bi | ⊢ ( 𝐾 ∈ Dirset → 𝐾 ∈ Proset ) |