Nuprl Lemma : final-iterate_wf

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


Proof




Definitions occuring in Statement :  final-iterate: final-iterate(f;x) p-graph: p-graph(A;f) strongwellfounded: SWellFounded(R[x; y]) uimplies: supposing a uall: [x:A]. B[x] top: Top member: t ∈ T apply: 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: supposing a member: t ∈ T all: x:A. B[x] prop: so_lambda: λ2y.t[x; y] cand: c∧ B subtype_rel: A ⊆B top: Top so_apply: x[s1;s2] strongwellfounded: SWellFounded(R[x; y]) exists: x:A. B[x] nat: implies:  Q false: False ge: i ≥  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 then else 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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