Metamath Proof Explorer


Theorem chub2

Description: Hilbert lattice join is greater than or equal to its second argument. (Contributed by NM, 12-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion chub2 ⊢ A ∈ C ℋ ∧ B ∈ C ℋ → A ⊆ B ∨ ℋ A

Proof

Step Hyp Ref Expression
1 chub1 ⊢ A ∈ C ℋ ∧ B ∈ C ℋ → A ⊆ A ∨ ℋ B
2 chjcom ⊢ A ∈ C ℋ ∧ B ∈ C ℋ → A ∨ ℋ B = B ∨ ℋ A
3 1 2 sseqtrd ⊢ A ∈ C ℋ ∧ B ∈ C ℋ → A ⊆ B ∨ ℋ A