Documentation

Mathlib.Order.PrimeSeparator

Separating prime filters and ideals #

In a bounded distributive lattice, if $F$ is a filter, $I$ is an ideal, and $F$ and $I$ are disjoint, then there exists a prime ideal $J$ containing $I$ with $J$ still disjoint from $F$. This theorem is a crucial ingredient to [Stone's][Sto1938] duality for bounded distributive lattices. The construction of the separator relies on Zorn's lemma.

Tags #

ideal, filter, prime, distributive lattice

References #

theorem DistribLattice.mem_ideal_sup_principal {α : Type u_1} [DistribLattice α] [BoundedOrder α] (a b : α) (J : Order.Ideal α) :
b J Order.Ideal.principal a jJ, b j a
theorem DistribLattice.prime_ideal_of_disjoint_filter_ideal {α : Type u_1} [DistribLattice α] [BoundedOrder α] {F : Order.PFilter α} {I : Order.Ideal α} (hFI : Disjoint F I) :
∃ (J : Order.Ideal α), J.IsPrime I J Disjoint F J