Nuprl Lemma : AF-induction

∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].
  (∀[Q:T ⟶ ℙ]. TI(T;x,y.¬R[x;y];t.Q[t])) supposing 
     (AFx,y:T.R[x;y] and 
     (∀x,y,z:T.  ((¬R[x;y]) ⇒ (¬R[y;z]) ⇒ (¬R[x;z]))))


Proof




Definitions occuring in Statement :  almost-full: AFx,y:T.R[x; y],  TI: TI(T;x,y.R[x; y];t.Q[t]),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s1;s2],  so_apply: x[s],  all: ∀x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  member: t ∈ T,  all: ∀x:A. B[x],  implies: P ⇒ Q,  not: ¬A,  false: False,  so_apply: x[s1;s2],  subtype_rel: A ⊆r B,  prop: ℙ,  almost-full: AFx,y:T.R[x; y],  squash: ↓T,  TI: TI(T;x,y.R[x; y];t.Q[t]),  so_lambda: λ2x y.t[x; y],  consistent-seq: R-consistent-seq(n),  so_lambda: λ2x.t[x],  so_apply: x[s],  exists: ∃x:A. B[x],  seq-add: s.x@n,  AF-spread-law: AF-spread-law(x,y.R[x; y]),  isl: isl(x),  outl: outl(x),  assert: ↑b,  ifthenelse: if b then t else f fi ,  btrue: tt,  int_seg: {i..j-},  nat: ℕ,  bool: 𝔹,  unit: Unit,  it: ⋅,  uiff: uiff(P;Q),  and: P ∧ Q,  cand: A c∧ B,  true: True,  bfalse: ff,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  lelt: i ≤ j < k,  le: A ≤ B,  decidable: Dec(P),  less_than': less_than'(a;b),  subtract: n - m,  sq_stable: SqStable(P),  top: Top,  less_than: a < b
Lemmas referenced :  not_wf,  nat_wf,  AF-spread-law_wf,  AFbar_wf,  basic_strong_bar_induction,  unit_wf2,  all_wf,  consistent-seq_wf,  decidable__AFbar,  at_AFbar,  AF-path-barred,  almost-full_wf,  eq_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  iff_transitivity,  assert_wf,  bnot_wf,  iff_weakening_uiff,  assert_of_bnot,  outl_wf,  decidable__lt,  false_wf,  not-lt-2,  not-equal-2,  add_functionality_wrt_le,  add-swap,  add-commutes,  le-add-cancel,  less-iff-le,  condition-implies-le,  add-associates,  minus-add,  minus-one-mul,  minus-one-mul-top,  zero-add,  le-add-cancel2,  int_seg_wf,  true_wf,  decidable__le,  not-le-2,  sq_stable__le,  add-zero,  le_wf,  seq-add_wf,  set_wf,  and_wf,  less_than_wf,  less_than_transitivity1,  less_than_irreflexivity
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  introduction,  sqequalRule,  sqequalHypSubstitution,  lambdaEquality,  dependent_functionElimination,  thin,  hypothesisEquality,  voidElimination,  applyEquality,  functionExtensionality,  cumulativity,  hypothesis,  universeEquality,  extract_by_obid,  isectElimination,  rename,  imageElimination,  imageMemberEquality,  baseClosed,  functionEquality,  lambdaFormation,  because_Cache,  unionEquality,  equalityTransitivity,  equalitySymmetry,  setEquality,  setElimination,  inlEquality,  independent_functionElimination,  dependent_set_memberEquality,  unionElimination,  equalityElimination,  productElimination,  independent_isectElimination,  int_eqReduceTrueSq,  natural_numberEquality,  independent_pairFormation,  dependent_pairFormation,  promote_hyp,  instantiate,  intEquality,  impliesFunctionality,  int_eqReduceFalseSq,  addEquality,  minusEquality,  isect_memberEquality,  voidEquality,  productEquality

Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    (\mforall{}[Q:T  {}\mrightarrow{}  \mBbbP{}].  TI(T;x,y.\mneg{}R[x;y];t.Q[t]))  supposing 
          (AFx,y:T.R[x;y]  and 
          (\mforall{}x,y,z:T.    ((\mneg{}R[x;y])  {}\mRightarrow{}  (\mneg{}R[y;z])  {}\mRightarrow{}  (\mneg{}R[x;z]))))



Date html generated: 2017_04_14-AM-07_27_57
Last ObjectModification: 2017_02_27-PM-02_57_29

Theory : bar-induction


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