Metamath Proof Explorer


Theorem odulat

Description: Being a lattice is self-dual. (Contributed by Stefan O'Rear, 29-Jan-2015)

Ref Expression
Hypothesis odulat.d ⊢ D = ODual ⁡ O
Assertion odulat ⊢ O ∈ Lat → D ∈ Lat

Proof

Step Hyp Ref Expression
1 odulat.d ⊢ D = ODual ⁡ O
2 1 odulatb ⊢ O ∈ Lat → O ∈ Lat ↔ D ∈ Lat
3 2 ibi ⊢ O ∈ Lat → D ∈ Lat