Nuprl Lemma : ss-mem-open-or

∀[X:SeparationSpace]. ∀T:Type. ∀F:T ⟶ Open(X). ∀x:Point(X).  (x ∈ ⋃t:T.F[t] ⇐⇒ ∃t:T. x ∈ F[t])


Proof




Definitions occuring in Statement :  ss-open-or: ⋃x:T.F[x],  ss-mem-open: x ∈ O,  ss-open: Open(X),  ss-point: Point(ss),  separation-space: SeparationSpace,  uall: ∀[x:A]. B[x],  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  ss-open-or: ⋃x:T.F[x],  ss-mem-open: x ∈ O,  exists: ∃x:A. B[x],  member: t ∈ T,  prop: ℙ,  so_apply: x[s],  subtype_rel: A ⊆r B,  ss-open: Open(X),  so_lambda: λ2x.t[x],  rev_implies: P ⇐ Q,  cand: A c∧ B
Lemmas referenced :  subtype_rel_self,  ss-basic_wf,  ss-mem-basic_wf,  exists_wf,  ss-mem-open_wf,  ss-open-or_wf,  ss-point_wf,  ss-open_wf,  separation-space_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  sqequalRule,  productElimination,  thin,  dependent_pairFormation,  hypothesisEquality,  hypothesis,  productEquality,  cut,  applyEquality,  instantiate,  introduction,  extract_by_obid,  isectElimination,  functionEquality,  cumulativity,  universeEquality,  lambdaEquality,  because_Cache

Latex:
\mforall{}[X:SeparationSpace].  \mforall{}T:Type.  \mforall{}F:T  {}\mrightarrow{}  Open(X).  \mforall{}x:Point(X).    (x  \mmember{}  \mcup{}t:T.F[t]  \mLeftarrow{}{}\mRightarrow{}  \mexists{}t:T.  x  \mmember{}  F[t])



Date html generated: 2020_05_20-PM-01_22_44
Last ObjectModification: 2018_07_06-PM-05_20_55

Theory : intuitionistic!topology


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