Metamath Proof Explorer


Theorem lplnbase

Description: A lattice plane is a lattice element. (Contributed by NM, 17-Jun-2012)

Ref Expression
Hypotheses lplnbase.b ⊢ B = Base K
lplnbase.p ⊢ P = LPlanes ⁡ K
Assertion lplnbase ⊢ X ∈ P → X ∈ B

Proof

Step Hyp Ref Expression
1 lplnbase.b ⊢ B = Base K
2 lplnbase.p ⊢ P = LPlanes ⁡ K
3 n0i ⊢ X ∈ P → ¬ P = ∅
4 2 eqeq1i ⊢ P = ∅ ↔ LPlanes ⁡ K = ∅
5 3 4 sylnib ⊢ X ∈ P → ¬ LPlanes ⁡ K = ∅
6 fvprc ⊢ ¬ K ∈ V → LPlanes ⁡ K = ∅
7 5 6 nsyl2 ⊢ X ∈ P → K ∈ V
8 eqid ⊢ ⋖ K = ⋖ K
9 eqid ⊢ LLines ⁡ K = LLines ⁡ K
10 1 8 9 2 islpln ⊢ K ∈ V → X ∈ P ↔ X ∈ B ∧ ∃ x ∈ LLines ⁡ K x ⋖ K X
11 10 simprbda ⊢ K ∈ V ∧ X ∈ P → X ∈ B
12 7 11 mpancom ⊢ X ∈ P → X ∈ B