Nuprl Lemma : final-iterate_wf

∀[A:Type]. ∀[f:A ⟶ (A + Top)].  ∀[x:A]. (final-iterate(f;x) ∈ A) supposing SWellFounded(p-graph(A;f) y x)


Proof




Definitions occuring in Statement :  final-iterate: final-iterate(f;x),  p-graph: p-graph(A;f),  strongwellfounded: SWellFounded(R[x; y]),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  top: Top,  member: t ∈ T,  apply: f a,  function: x:A ⟶ B[x],  union: left + right,  universe: Type
Definitions unfolded in proof :  p-graph: p-graph(A;f),  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  member: t ∈ T,  all: ∀x:A. B[x],  prop: ℙ,  so_lambda: λ2x y.t[x; y],  cand: A c∧ B,  subtype_rel: A ⊆r B,  top: Top,  so_apply: x[s1;s2],  strongwellfounded: SWellFounded(R[x; y]),  exists: ∃x:A. B[x],  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  not: ¬A,  and: P ∧ Q,  final-iterate: final-iterate(f;x),  decidable: Dec(P),  or: P ∨ Q,  guard: {T},  less_than: a < b,  squash: ↓T,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  ifthenelse: if b then t else f fi ,  bfalse: ff
Lemmas referenced :  strongwellfounded_wf,  assert_wf,  can-apply_wf,  subtype_rel_union,  top_wf,  equal_wf,  do-apply_wf,  nat_properties,  satisfiable-full-omega-tt,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  ge_wf,  less_than_wf,  le_wf,  nat_wf,  decidable__le,  subtract_wf,  intformnot_wf,  itermSubtract_wf,  int_formula_prop_not_lemma,  int_term_value_subtract_lemma,  bool_wf,  equal-wf-T-base,  bnot_wf,  not_wf,  eqtt_to_assert,  uiff_transitivity,  eqff_to_assert,  assert_of_bnot
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  introduction,  cut,  thin,  sqequalHypSubstitution,  dependent_functionElimination,  hypothesisEquality,  equalityTransitivity,  hypothesis,  equalitySymmetry,  axiomEquality,  extract_by_obid,  isectElimination,  cumulativity,  lambdaEquality,  productEquality,  functionExtensionality,  applyEquality,  because_Cache,  independent_isectElimination,  isect_memberEquality,  voidElimination,  voidEquality,  functionEquality,  unionEquality,  universeEquality,  productElimination,  lambdaFormation,  setElimination,  rename,  intWeakElimination,  natural_numberEquality,  dependent_pairFormation,  int_eqEquality,  intEquality,  independent_pairFormation,  computeAll,  independent_functionElimination,  unionElimination,  applyLambdaEquality,  baseClosed,  imageElimination,  equalityElimination

Latex:
\mforall{}[A:Type].  \mforall{}[f:A  {}\mrightarrow{}  (A  +  Top)].
    \mforall{}[x:A].  (final-iterate(f;x)  \mmember{}  A)  supposing  SWellFounded(p-graph(A;f)  y  x)



Date html generated: 2018_05_21-PM-07_36_42
Last ObjectModification: 2017_07_26-PM-05_10_42

Theory : general


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