Nuprl Lemma : dfan-implies-twkl!

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


Proof




Definitions occuring in Statement :  twkl!: WKL!(T),  dfan: Fan_d(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 :  nat: ℕ,  exists: ∃x:A. B[x],  prop: ℙ,  subtype_rel: A ⊆r B,  and: P ∧ Q,  false: False,  not: ¬A,  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x]
Lemmas referenced :  fan-implies-barred-not-unbounded,  fan-implies-bar-sep,  istype-universe,  int_seg_wf,  equipollent_wf,  istype-nat,  dfan_wf,  dbar_wf,  unbounded-list-predicate_wf,  subtype_rel_self,  list_wf,  predicate-not_wf,  down-closed_wf,  bar-separation-implies-twkl!
Rules used in proof :  dependent_functionElimination,  rename,  setElimination,  natural_numberEquality,  Error :functionIsType,  because_Cache,  universeEquality,  instantiate,  applyEquality,  functionExtensionality,  Error :universeIsType,  Error :productIsType,  sqequalRule,  voidElimination,  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\_d(T)  {}\mRightarrow{}  WKL!(T))



Date html generated: 2019_06_20-PM-02_48_11
Last ObjectModification: 2019_06_05-PM-04_27_12

Theory : fan-theorem


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