Nuprl Lemma : open-isect_wf

[X:Type]. ∀[A,B:Open(X)].  (open-isect(A;B) ∈ Open(X))


Proof




Definitions occuring in Statement :  open-isect: open-isect(A;B) Open: Open(X) uall: [x:A]. B[x] member: t ∈ T universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T open-isect: open-isect(A;B) Open: Open(X) subtype_rel: A ⊆B
Lemmas referenced :  sp-meet_wf Sierpinski_wf Open_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule lambdaEquality lemma_by_obid sqequalHypSubstitution isectElimination thin applyEquality hypothesisEquality hypothesis functionEquality axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality because_Cache universeEquality

Latex:
\mforall{}[X:Type].  \mforall{}[A,B:Open(X)].    (open-isect(A;B)  \mmember{}  Open(X))



Date html generated: 2019_10_31-AM-07_18_50
Last ObjectModification: 2015_12_28-AM-11_20_57

Theory : synthetic!topology


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