Nuprl Lemma : rpowers-converge

∀x:ℝ. (((|x| < r1) ⇒ lim n→∞.x^n = r0) ∧ ((r1 < x) ⇒ lim n →∞.x^n = ∞))


Proof




Definitions occuring in Statement :  converges-to-infinity: lim n →∞.x[n] = ∞,  converges-to: lim n→∞.x[n] = y,  rless: x < y,  rabs: |x|,  rnexp: x^k1,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  and: P ∧ Q,  cand: A c∧ B,  implies: P ⇒ Q,  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  exists: ∃x:A. B[x],  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  itermConstant: "const",  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  uiff: uiff(P;Q),  rdiv: (x/y),  all-large: ∀large(n).P[n],  converges-to-infinity: lim n →∞.x[n] = ∞,  nat_plus: ℕ+,  satisfiable_int_formula: satisfiable_int_formula(fmla),  decidable: Dec(P),  sq_stable: SqStable(P),  real: ℝ,  subtype_rel: A ⊆r B,  sq_exists: ∃x:{A| B[x]},  rless: x < y,  nat: ℕ,  so_apply: x[s],  so_lambda: λ2x.t[x],  ge: i ≥ j ,  subtract: n - m,  le: A ≤ B,  rnonneg: rnonneg(x),  rleq: x ≤ y
Lemmas referenced :  rnexp-converges,  rless_wf,  rabs_wf,  int-to-real_wf,  real_wf,  rdiv_wf,  rsub_wf,  rless-int,  rmul_preserves_rless,  radd_wf,  rmul_wf,  rminus_wf,  rinv_wf2,  rless-implies-rless,  real_term_polynomial,  itermSubtract_wf,  itermVar_wf,  itermConstant_wf,  itermAdd_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_var_lemma,  real_term_value_add_lemma,  req-iff-rsub-is-0,  itermMultiply_wf,  real_term_value_mul_lemma,  rless_functionality,  req_transitivity,  itermMinus_wf,  real_term_value_minus_lemma,  radd_functionality,  rmul_functionality,  rmul-rinv,  req_weakening,  rmul-identity1,  rminus_functionality,  squash_wf,  true_wf,  rminus-int,  rleq-int,  rmul_preserves_rleq2,  rleq_weakening_rless,  less_than'_wf,  radd-preserves-rleq,  subtract_wf,  radd-preserves-rless,  rless_transitivity1,  rdiv_functionality,  rsub-int,  rmul-rdiv-cancel2,  radd-int,  add-commutes,  add-swap,  add-associates,  zero-add,  nat_properties,  nat_wf,  all_wf,  rleq_wf,  rnexp_wf,  rabs-bounds,  rleq_transitivity,  rless_transitivity2,  nat_plus_properties,  sq_stable__less_than,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  le_wf,  decidable__lt,  less_than_wf,  integer-bound,  nat_plus_wf,  rpower-greater-one
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  hypothesis,  isectElimination,  natural_numberEquality,  independent_pairFormation,  dependent_pairFormation,  independent_isectElimination,  sqequalRule,  inrFormation,  because_Cache,  productElimination,  imageMemberEquality,  baseClosed,  productEquality,  minusEquality,  computeAll,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  applyEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  lemma_by_obid,  rename,  setElimination,  unionElimination,  addEquality,  dependent_set_memberEquality,  functionEquality,  promote_hyp,  axiomEquality,  independent_pairEquality,  isect_memberFormation

Latex:
\mforall{}x:\mBbbR{}.  (((|x|  <  r1)  {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.x\^{}n  =  r0)  \mwedge{}  ((r1  <  x)  {}\mRightarrow{}  lim  n  \mrightarrow{}\minfty{}.x\^{}n  =  \minfty{}))



Date html generated: 2017_10_03-AM-08_54_50
Last ObjectModification: 2017_07_28-AM-07_36_45

Theory : reals


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