Nuprl Lemma : fan-wkl!

∀[T:Type]. ((∃size:ℕ. T ~ ℕsize) ⇒ Fan(T) ⇒ WKL!(T))


Proof




Definitions occuring in Statement :  alt-wkl!: WKL!(T),  altfan: Fan(T),  equipollent: A ~ B,  int_seg: {i..j-},  nat: ℕ,  uall: ∀[x:A]. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  natural_number: $n,  universe: Type
Definitions unfolded in proof :  exists: ∃x:A. B[x],  and: P ∧ Q,  nat: ℕ,  prop: ℙ,  uimplies: b supposing a,  false: False,  not: ¬A,  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x]
Lemmas referenced :  istype-universe,  equipollent_wf,  altfan_wf,  altunbounded_wf,  alttree_wf,  bool_wf,  int_seg_wf,  istype-nat,  altneg_wf,  altbar_wf,  istype-void,  complement-unbounded-tree,  fan-bar-sep,  alt-bar-sep-wkl!
Rules used in proof :  universeEquality,  instantiate,  Error :productIsType,  natural_numberEquality,  Error :setIsType,  rename,  setElimination,  Error :universeIsType,  dependent_functionElimination,  Error :inhabitedIsType,  Error :functionIsType,  sqequalRule,  voidElimination,  independent_isectElimination,  independent_functionElimination,  Error :lambdaFormation_alt,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  hypothesis,  Error :isect_memberFormation_alt,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  extract_by_obid,  introduction,  cut

Latex:
\mforall{}[T:Type].  ((\mexists{}size:\mBbbN{}.  T  \msim{}  \mBbbN{}size)  {}\mRightarrow{}  Fan(T)  {}\mRightarrow{}  WKL!(T))



Date html generated: 2019_06_20-PM-02_46_57
Last ObjectModification: 2019_06_07-PM-00_00_05

Theory : fan-theorem


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