Nuprl Lemma : weakly-infinite-cases

∀[S:ℕ ⟶ ℙ]. (w∃∞x.S[x] ⇒ (∀[A:ℕ ⟶ ℙ]. ((∀n:ℕ. (A[n] ⇒ S[n])) ⇒ (¬¬(w∃∞n.A[n] ∨ w∃∞n.S[n] ∧ (¬A[n]))))))


Proof




Definitions occuring in Statement :  weakly-infinite: w∃∞p.S[p],  nat: ℕ,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s],  all: ∀x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  or: P ∨ Q,  and: P ∧ Q,  function: x:A ⟶ B[x]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  not: ¬A,  false: False,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s],  and: P ∧ Q,  subtype_rel: A ⊆r B,  or: P ∨ Q,  all: ∀x:A. B[x],  nat: ℕ,  exists: ∃x:A. B[x],  uiff: uiff(P;Q),  uimplies: b supposing a,  weakly-infinite: w∃∞p.S[p],  iff: P ⇐⇒ Q,  guard: {T},  decidable: Dec(P),  cand: A c∧ B,  le: A ≤ B,  rev_implies: P ⇐ Q,  subtract: n - m,  top: Top,  less_than': less_than'(a;b),  true: True
Lemmas referenced :  not_wf,  or_wf,  weakly-infinite_wf,  nat_wf,  all_wf,  false_wf,  exists_wf,  less_than_wf,  not_over_exists,  minimal-double-negation-hyp-elim,  minimal-not-not-excluded-middle,  dneg_elim_a,  double-negation-hyp-elim,  decidable__le,  le_weakening,  le_wf,  le_reflexive,  not-le-2,  condition-implies-le,  minus-add,  minus-one-mul,  add-swap,  minus-one-mul-top,  add-commutes,  add_functionality_wrt_le,  add-associates,  le-add-cancel,  less_than_transitivity2
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  lambdaFormation,  thin,  hypothesis,  sqequalHypSubstitution,  independent_functionElimination,  voidElimination,  extract_by_obid,  isectElimination,  sqequalRule,  lambdaEquality,  applyEquality,  functionExtensionality,  hypothesisEquality,  productEquality,  universeEquality,  functionEquality,  dependent_functionElimination,  because_Cache,  cumulativity,  isect_memberEquality,  inlFormation,  setElimination,  rename,  productElimination,  independent_isectElimination,  unionElimination,  dependent_pairFormation,  addLevel,  impliesFunctionality,  levelHypothesis,  inrFormation,  independent_pairFormation,  addEquality,  natural_numberEquality,  voidEquality,  intEquality,  minusEquality,  promote_hyp

Latex:
\mforall{}[S:\mBbbN{}  {}\mrightarrow{}  \mBbbP{}]
    (w\mexists{}\minfty{}x.S[x]  {}\mRightarrow{}  (\mforall{}[A:\mBbbN{}  {}\mrightarrow{}  \mBbbP{}].  ((\mforall{}n:\mBbbN{}.  (A[n]  {}\mRightarrow{}  S[n]))  {}\mRightarrow{}  (\mneg{}\mneg{}(w\mexists{}\minfty{}n.A[n]  \mvee{}  w\mexists{}\minfty{}n.S[n]  \mwedge{}  (\mneg{}A[n]))))))



Date html generated: 2017_09_29-PM-05_47_37
Last ObjectModification: 2017_07_26-PM-01_25_15

Theory : bar-induction


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