Nuprl Lemma : dec-exists-int-seg

∀a,b:ℤ.  ∀[F:{a..b-} ⟶ ℙ]. ((∀k:{a..b-}. Dec(F[k])) ⇒ Dec(∃k:{a..b-}. F[k]))


Proof




Definitions occuring in Statement :  int_seg: {i..j-},  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],  int: ℤ
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  prop: ℙ
Lemmas referenced :  decidable_wf,  all_wf,  int_seg_wf,  decidable__exists_int_seg
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  isect_memberFormation,  cut,  thin,  instantiate,  lemma_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  hypothesisEquality,  isectElimination,  sqequalRule,  lambdaEquality,  applyEquality,  hypothesis,  independent_functionElimination,  functionEquality,  cumulativity,  universeEquality,  intEquality

Latex:
\mforall{}a,b:\mBbbZ{}.    \mforall{}[F:\{a..b\msupminus{}\}  {}\mrightarrow{}  \mBbbP{}].  ((\mforall{}k:\{a..b\msupminus{}\}.  Dec(F[k]))  {}\mRightarrow{}  Dec(\mexists{}k:\{a..b\msupminus{}\}.  F[k]))



Date html generated: 2016_05_14-PM-09_56_16
Last ObjectModification: 2016_01_16-PM-05_37_41

Theory : continuity


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