Nuprl Lemma : W-uniform-measure-induction

∀[T,A:Type]. ∀[B:A ⟶ Type]. ∀[measure:T ⟶ W(A;a.B[a])]. ∀[P:T ⟶ ℙ].
  ((∀[i:T]. ((∀[j:{j:T| measure[j] <  measure[i]} ]. P[j]) ⇒ P[i])) ⇒ (∀[i:T]. P[i]))


Proof




Definitions occuring in Statement :  Wcmp: Wcmp(A;a.B[a];leq),  W: W(A;a.B[a]),  bfalse: ff,  uall: ∀[x:A]. B[x],  prop: ℙ,  infix_ap: x f y,  so_apply: x[s],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  member: t ∈ T,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  so_lambda: λ2x.t[x],  so_apply: x[s],  subtype_rel: A ⊆r B,  prop: ℙ,  uimplies: b supposing a,  Wcmp: Wcmp(A;a.B[a];leq),  Wsup: Wsup(a;b),  infix_ap: x f y,  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  guard: {T},  top: Top,  and: P ∧ Q,  pcw-pp-barred: Barred(pp),  nat: ℕ,  int_seg: {i..j-},  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  iff: P ⇐⇒ Q,  not: ¬A,  rev_implies: P ⇐ Q,  false: False,  uiff: uiff(P;Q),  subtract: n - m,  le: A ≤ B,  less_than': less_than'(a;b),  true: True,  cw-step: cw-step(A;a.B[a]),  pcw-step: pcw-step(P;p.A[p];p,a.B[p; a];p,a,b.C[p; a; b]),  spreadn: spread3,  less_than: a < b,  squash: ↓T,  isr: isr(x),  assert: ↑b,  btrue: tt,  ext-eq: A ≡ B,  unit: Unit,  it: ⋅,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  ext-family: F ≡ G,  pi1: fst(t),  nat_plus: ℕ+,  istype: istype(T),  W-rel: W-rel(A;a.B[a];w),  param-W-rel: param-W-rel(P;p.A[p];p,a.B[p; a];p,a,b.C[p; a; b];par;w),  pcw-steprel: StepRel(s1;s2),  pi2: snd(t),  isl: isl(x),  pcw-step-agree: StepAgree(s;p1;w),  cand: A c∧ B,  sq_type: SQType(T),  sq_stable: SqStable(P)
Lemmas referenced :  infix_ap_wf,  W_wf,  Wcmp_wf,  bfalse_wf,  ycomb_wf_trivial,  Wleq_weakening2,  ycomb-unroll,  istype-void,  btrue_wf,  Wsup_wf,  W-elimination-facts,  subtype_rel_self,  int_seg_wf,  subtract_wf,  decidable__le,  istype-false,  not-le-2,  less-iff-le,  condition-implies-le,  minus-one-mul,  zero-add,  minus-one-mul-top,  nat_wf,  minus-add,  istype-int,  minus-minus,  add-associates,  add-swap,  add-commutes,  add_functionality_wrt_le,  add-zero,  le-add-cancel,  decidable__lt,  not-lt-2,  add-mul-special,  zero-mul,  le-add-cancel-alt,  lelt_wf,  istype-top,  true_wf,  add-subtract-cancel,  W-ext,  param-co-W-ext,  unit_wf2,  it_wf,  param-co-W_wf,  less_than_wf,  top_wf,  pcw-steprel_wf,  false_wf,  subtype_rel_dep_function,  subtype_base_sq,  set_subtype_base,  le_wf,  int_subtype_base,  minus-zero,  le-add-cancel2,  decidable__int_equal,  not-equal-2,  subtype_rel_function,  int_seg_subtype,  sq_stable__le,  Wcmp_transitivity
Rules used in proof :  introduction,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  sqequalRule,  Error :isect_memberEquality_alt,  cut,  Error :lambdaFormation_alt,  rename,  Error :universeIsType,  hypothesisEquality,  sqequalHypSubstitution,  hypothesis,  Error :isectIsType,  Error :functionIsType,  Error :setIsType,  Error :inhabitedIsType,  thin,  instantiate,  extract_by_obid,  isectElimination,  cumulativity,  Error :lambdaEquality_alt,  applyEquality,  functionExtensionality,  because_Cache,  equalityTransitivity,  equalitySymmetry,  universeEquality,  setElimination,  Error :functionExtensionality_alt,  dependent_functionElimination,  independent_functionElimination,  independent_isectElimination,  productElimination,  voidElimination,  strong_bar_Induction,  natural_numberEquality,  Error :dependent_set_memberEquality_alt,  independent_pairFormation,  unionElimination,  addEquality,  minusEquality,  lessCases,  Error :isect_memberFormation_alt,  axiomSqEquality,  imageMemberEquality,  baseClosed,  imageElimination,  axiomEquality,  Error :equalityIsType1,  int_eqReduceTrueSq,  promote_hyp,  hypothesis_subsumption,  equalityElimination,  Error :dependent_pairEquality_alt,  Error :inlEquality_alt,  Error :unionIsType,  productEquality,  unionEquality,  hyp_replacement,  applyLambdaEquality,  intEquality

Latex:
\mforall{}[T,A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].  \mforall{}[measure:T  {}\mrightarrow{}  W(A;a.B[a])].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}[i:T].  ((\mforall{}[j:\{j:T|  measure[j]  <    measure[i]\}  ].  P[j])  {}\mRightarrow{}  P[i]))  {}\mRightarrow{}  (\mforall{}[i:T].  P[i]))



Date html generated: 2019_06_20-PM-00_36_39
Last ObjectModification: 2018_10_01-PM-03_05_32

Theory : co-recursion


Home Index