Nuprl Lemma : ss-open-and_wf

[X:SeparationSpace]. ∀[A,B:Open(X)].  (A ⋂ B ∈ Open(X))


Proof




Definitions occuring in Statement :  ss-open-and: A ⋂ B ss-open: Open(X) separation-space: SeparationSpace uall: [x:A]. B[x] member: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T ss-open-and: A ⋂ B so_lambda: λ2x.t[x] prop: and: P ∧ Q ss-open: Open(X) subtype_rel: A ⊆B so_apply: x[s]
Lemmas referenced :  exists_wf ss-basic_wf subtype_rel_self equal_wf ss-basic-and_wf ss-open_wf separation-space_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule lambdaEquality extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis productEquality applyEquality instantiate universeEquality because_Cache axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality

Latex:
\mforall{}[X:SeparationSpace].  \mforall{}[A,B:Open(X)].    (A  \mcap{}  B  \mmember{}  Open(X))



Date html generated: 2020_05_20-PM-01_22_35
Last ObjectModification: 2018_07_06-PM-04_49_20

Theory : intuitionistic!topology


Home Index