Nuprl Lemma : decidable__wellfound-bounded-exists

∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ]. ∀[P:T ⟶ ℙ].
  ((∀x,y:T.  Dec(R x y))
  ⇒ (∀x:T. Dec(P[x]))
  ⇒ (∀y:T. ∃L:T List. ∀x:T. ((R x y) ⇒ (x ∈ L)))
  ⇒ WellFnd{i}(T;x,y.R x y)
  ⇒ (∀y:T. Dec(∃x:T. ((R+ x y) ∧ P[x]))))


Proof




Definitions occuring in Statement :  rel_plus: R+,  l_member: (x ∈ l),  list: T List,  wellfounded: WellFnd{i}(A;x,y.R[x; y]),  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,  and: P ∧ Q,  apply: f a,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  wellfounded: WellFnd{i}(A;x,y.R[x; y]),  so_lambda: λ2x.t[x],  member: t ∈ T,  prop: ℙ,  subtype_rel: A ⊆r B,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  guard: {T},  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  and: P ∧ Q,  cand: A c∧ B,  decidable: Dec(P),  or: P ∨ Q,  l_exists: (∃x∈L. P[x]),  int_seg: {i..j-},  uimplies: b supposing a,  lelt: i ≤ j < k,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  not: ¬A,  top: Top,  less_than: a < b,  squash: ↓T,  infix_ap: x f y,  trans: Trans(T;x,y.E[x; y]),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  l_exists_iff,  rel_plus_implies,  rel_plus_trans,  rel-rel-plus,  int_formula_prop_less_lemma,  intformless_wf,  decidable__lt,  int_formula_prop_wf,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermVar_wf,  itermConstant_wf,  intformle_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__le,  length_wf,  int_seg_properties,  select_wf,  not_wf,  decidable__cand,  decidable__l_exists_better-extract,  decidable__and,  decidable__l_exists,  l_member_wf,  list_wf,  wellfounded_wf,  all_wf,  rel_plus_wf,  and_wf,  exists_wf,  decidable_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  sqequalHypSubstitution,  cut,  hypothesis,  isectElimination,  thin,  sqequalRule,  lambdaEquality,  lemma_by_obid,  hypothesisEquality,  applyEquality,  because_Cache,  independent_functionElimination,  rename,  dependent_functionElimination,  productElimination,  functionEquality,  cumulativity,  universeEquality,  isect_memberEquality,  unionElimination,  inlFormation,  dependent_pairFormation,  setElimination,  independent_isectElimination,  natural_numberEquality,  int_eqEquality,  intEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  imageElimination,  inrFormation,  productEquality,  setEquality

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}x,y:T.    Dec(R  x  y))
    {}\mRightarrow{}  (\mforall{}x:T.  Dec(P[x]))
    {}\mRightarrow{}  (\mforall{}y:T.  \mexists{}L:T  List.  \mforall{}x:T.  ((R  x  y)  {}\mRightarrow{}  (x  \mmember{}  L)))
    {}\mRightarrow{}  WellFnd\{i\}(T;x,y.R  x  y)
    {}\mRightarrow{}  (\mforall{}y:T.  Dec(\mexists{}x:T.  ((R\msupplus{}  x  y)  \mwedge{}  P[x]))))



Date html generated: 2016_05_15-PM-04_52_03
Last ObjectModification: 2016_01_16-AM-11_29_16

Theory : general


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