Metamath Proof Explorer


Theorem latmle1

Description: A meet is less than or equal to its first argument. (Contributed by NM, 21-Oct-2011)

Ref Expression
Hypotheses latmle.b ⊢ B = Base K
latmle.l ⊢ ≤ ˙ = ≤ K
latmle.m ⊢ ∧ ˙ = meet ⁡ K
Assertion latmle1 ⊢ K ∈ Lat ∧ X ∈ B ∧ Y ∈ B → X ∧ ˙ Y ≤ ˙ X

Proof

Step Hyp Ref Expression
1 latmle.b ⊢ B = Base K
2 latmle.l ⊢ ≤ ˙ = ≤ K
3 latmle.m ⊢ ∧ ˙ = meet ⁡ K
4 simp1 ⊢ K ∈ Lat ∧ X ∈ B ∧ Y ∈ B → K ∈ Lat
5 simp2 ⊢ K ∈ Lat ∧ X ∈ B ∧ Y ∈ B → X ∈ B
6 simp3 ⊢ K ∈ Lat ∧ X ∈ B ∧ Y ∈ B → Y ∈ B
7 eqid ⊢ join ⁡ K = join ⁡ K
8 1 7 3 4 5 6 latcl2 ⊢ K ∈ Lat ∧ X ∈ B ∧ Y ∈ B → X Y ∈ dom ⁡ join ⁡ K ∧ X Y ∈ dom ⁡ ∧ ˙
9 8 simprd ⊢ K ∈ Lat ∧ X ∈ B ∧ Y ∈ B → X Y ∈ dom ⁡ ∧ ˙
10 1 2 3 4 5 6 9 lemeet1 ⊢ K ∈ Lat ∧ X ∈ B ∧ Y ∈ B → X ∧ ˙ Y ≤ ˙ X