Nuprl Lemma : fan_theorem-ext

∀[X:n:ℕ ⟶ (ℕn ⟶ 𝔹) ⟶ ℙ]
  (∀n:ℕ. ∀s:ℕn ⟶ 𝔹.  Dec(X[n;s])) ⇒ (∃k:ℕ. ∀f:ℕ ⟶ 𝔹. ∃n:ℕk. X[n;f]) supposing ∀f:ℕ ⟶ 𝔹. (↓∃n:ℕ. X[n;f])


Proof




Definitions occuring in Statement :  int_seg: {i..j-},  nat: ℕ,  bool: 𝔹,  decidable: Dec(P),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s1;s2],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  squash: ↓T,  implies: P ⇒ Q,  function: x:A ⟶ B[x],  natural_number: $n
Definitions unfolded in proof :  member: t ∈ T,  fan_theorem,  simple_fan_theorem'-ext
Lemmas referenced :  fan_theorem,  simple_fan_theorem'-ext
Rules used in proof :  introduction,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  thin,  sqequalHypSubstitution,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[X:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbB{})  {}\mrightarrow{}  \mBbbP{}]
    (\mforall{}n:\mBbbN{}.  \mforall{}s:\mBbbN{}n  {}\mrightarrow{}  \mBbbB{}.    Dec(X[n;s]))  {}\mRightarrow{}  (\mexists{}k:\mBbbN{}.  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  \mexists{}n:\mBbbN{}k.  X[n;f]) 
    supposing  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  (\mdownarrow{}\mexists{}n:\mBbbN{}.  X[n;f])



Date html generated: 2019_06_20-PM-01_15_32
Last ObjectModification: 2019_03_12-PM-04_25_58

Theory : int_2


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