Nuprl Lemma : decidable-exists-finite

∀[T:Type]. (finite(T) ⇒ (∀[P:T ⟶ ℙ]. ((∀t:T. Dec(P[t])) ⇒ Dec(∃t:T. P[t]))))


Proof




Definitions occuring in Statement :  finite: finite(T),  decidable: Dec(P),  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  prop: ℙ,  finite: finite(T),  exists: ∃x:A. B[x],  finite-type: finite-type(T),  nat: ℕ,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T},  equipollent: A ~ B,  biject: Bij(A;B;f),  and: P ∧ Q
Lemmas referenced :  decidable-exists-finite-type,  finite_wf,  exists_wf,  int_seg_wf,  surject_wf,  equipollent_inversion
Rules used in proof :  cut,  introduction,  extract_by_obid,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  lambdaFormation,  independent_functionElimination,  cumulativity,  universeEquality,  productElimination,  dependent_pairFormation,  functionEquality,  natural_numberEquality,  setElimination,  rename,  sqequalRule,  lambdaEquality,  because_Cache,  functionExtensionality,  applyEquality

Latex:
\mforall{}[T:Type].  (finite(T)  {}\mRightarrow{}  (\mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].  ((\mforall{}t:T.  Dec(P[t]))  {}\mRightarrow{}  Dec(\mexists{}t:T.  P[t]))))



Date html generated: 2016_10_21-AM-11_00_13
Last ObjectModification: 2016_08_08-AM-11_27_08

Theory : equipollence!!cardinality!


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