Metamath Proof Explorer


Theorem atdmd2

Description: Two Hilbert lattice elements have the dual modular pair property if the second is an atom. (Contributed by NM, 6-Jul-2004) (New usage is discouraged.)

Ref Expression
Assertion atdmd2 A C B HAtoms A 𝑀 * B

Proof

Step Hyp Ref Expression
1 atdmd B HAtoms A C B 𝑀 * A
2 1 ancoms A C B HAtoms B 𝑀 * A
3 atelch B HAtoms B C
4 dmdsym A C B C A 𝑀 * B B 𝑀 * A
5 3 4 sylan2 A C B HAtoms A 𝑀 * B B 𝑀 * A
6 2 5 mpbird A C B HAtoms A 𝑀 * B