Metamath Proof Explorer


Theorem cmdmdi

Description: Commuting subspaces form a dual modular pair. (Contributed by NM, 25-Apr-2006) (New usage is discouraged.)

Ref Expression
Hypotheses sumdmdi.1 ⊢ A ∈ C ℋ
sumdmdi.2 ⊢ B ∈ C ℋ
Assertion cmdmdi ⊢ A 𝐶 ℋ B → A 𝑀 ℋ * B

Proof

Step Hyp Ref Expression
1 sumdmdi.1 ⊢ A ∈ C ℋ
2 sumdmdi.2 ⊢ B ∈ C ℋ
3 1 choccli ⊢ ⊥ ⁡ A ∈ C ℋ
4 2 choccli ⊢ ⊥ ⁡ B ∈ C ℋ
5 3 4 cmmdi ⊢ ⊥ ⁡ A 𝐶 ℋ ⊥ ⁡ B → ⊥ ⁡ A 𝑀 ℋ ⊥ ⁡ B
6 1 2 cmcm4i ⊢ A 𝐶 ℋ B ↔ ⊥ ⁡ A 𝐶 ℋ ⊥ ⁡ B
7 dmdmd ⊢ A ∈ C ℋ ∧ B ∈ C ℋ → A 𝑀 ℋ * B ↔ ⊥ ⁡ A 𝑀 ℋ ⊥ ⁡ B
8 1 2 7 mp2an ⊢ A 𝑀 ℋ * B ↔ ⊥ ⁡ A 𝑀 ℋ ⊥ ⁡ B
9 5 6 8 3imtr4i ⊢ A 𝐶 ℋ B → A 𝑀 ℋ * B