Nuprl Lemma : fun_exp-fixedpoint

∀[T:Type]. ∀[f:T ⟶ T]. ∀[x:T].  ∀[n:ℕ]. ((f^n x) = x ∈ T) supposing (f x) = x ∈ T


Proof




Definitions occuring in Statement :  fun_exp: f^n,  nat: ℕ,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  apply: f a,  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  guard: {T},  prop: ℙ,  all: ∀x:A. B[x],  top: Top,  decidable: Dec(P),  or: P ∨ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  not: ¬A,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  subtract: n - m,  subtype_rel: A ⊆r B,  le: A ≤ B,  less_than': less_than'(a;b),  true: True,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  bfalse: ff,  compose: f o g
Lemmas referenced :  nat_properties,  less_than_transitivity1,  less_than_irreflexivity,  ge_wf,  less_than_wf,  fun_exp0_lemma,  decidable__le,  subtract_wf,  false_wf,  not-ge-2,  less-iff-le,  condition-implies-le,  minus-one-mul,  zero-add,  minus-one-mul-top,  minus-add,  minus-minus,  add-associates,  add-swap,  add-commutes,  add_functionality_wrt_le,  add-zero,  le-add-cancel,  nat_wf,  equal_wf,  fun_exp_unroll,  le_weakening2,  le_wf,  eq_int_wf,  bool_wf,  equal-wf-base,  int_subtype_base,  assert_wf,  le_weakening,  bnot_wf,  not_wf,  uiff_transitivity,  eqtt_to_assert,  assert_of_eq_int,  iff_transitivity,  iff_weakening_uiff,  eqff_to_assert,  assert_of_bnot,  and_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  setElimination,  rename,  intWeakElimination,  lambdaFormation,  natural_numberEquality,  independent_isectElimination,  independent_functionElimination,  voidElimination,  sqequalRule,  lambdaEquality,  dependent_functionElimination,  axiomEquality,  isect_memberEquality,  voidEquality,  unionElimination,  independent_pairFormation,  productElimination,  addEquality,  applyEquality,  intEquality,  minusEquality,  because_Cache,  cumulativity,  functionExtensionality,  equalityTransitivity,  equalitySymmetry,  functionEquality,  universeEquality,  dependent_set_memberEquality,  baseApply,  closedConclusion,  baseClosed,  equalityElimination,  impliesFunctionality,  hyp_replacement,  applyLambdaEquality

Latex:
\mforall{}[T:Type].  \mforall{}[f:T  {}\mrightarrow{}  T].  \mforall{}[x:T].    \mforall{}[n:\mBbbN{}].  ((f\^{}n  x)  =  x)  supposing  (f  x)  =  x



Date html generated: 2017_04_14-AM-07_35_00
Last ObjectModification: 2017_02_27-PM-03_07_54

Theory : fun_1


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