Nuprl Lemma : rinv-limit

∀x:ℕ ⟶ ℝ. ∀a:ℝ.  (lim n→∞.x[n] = a ⇒ (∀n:ℕ. x[n] ≠ r0) ⇒ a ≠ r0 ⇒ lim n→∞.(r1/x[n]) = (r1/a))


Proof




Definitions occuring in Statement :  converges-to: lim n→∞.x[n] = y,  rdiv: (x/y),  rneq: x ≠ y,  int-to-real: r(n),  real: ℝ,  nat: ℕ,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x],  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  converges-to: lim n→∞.x[n] = y,  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  so_apply: x[s],  so_lambda: λ2x.t[x],  uiff: uiff(P;Q),  and: P ∧ Q,  rev_uimplies: rev_uimplies(P;Q),  uimplies: b supposing a,  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  rsub: x - y,  rge: x ≥ y,  guard: {T},  rneq: x ≠ y,  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  nat_plus: ℕ+,  rless: x < y,  sq_exists: ∃x:A [B[x]],  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  rdiv: (x/y),  sq-all-large: ∀large(n).{P[n]},  nat: ℕ,  rat_term_to_real: rat_term_to_real(f;t),  rtermDivide: num "/" denom,  rat_term_ind: rat_term_ind,  rtermVar: rtermVar(var),  rtermConstant: "const",  pi1: fst(t),  rtermMultiply: left "*" right,  pi2: snd(t),  ge: i ≥ j ,  subtype_rel: A ⊆r B,  absval: |i|,  cand: A c∧ B,  int_nzero: ℤ-o,  nequal: a ≠ b ∈ T ,  sq_type: SQType(T)
Lemmas referenced :  rneq_wf,  int-to-real_wf,  istype-nat,  converges-to_wf,  real_wf,  radd-preserves-rleq,  rsub_wf,  rabs_wf,  radd_wf,  rminus_wf,  itermSubtract_wf,  itermAdd_wf,  itermVar_wf,  itermMinus_wf,  rleq_functionality,  radd_functionality,  req_weakening,  rabs_functionality,  req-iff-rsub-is-0,  real_polynomial_null,  istype-int,  real_term_value_sub_lemma,  istype-void,  real_term_value_add_lemma,  real_term_value_var_lemma,  real_term_value_const_lemma,  real_term_value_minus_lemma,  rleq_weakening_equal,  rabs-difference-symmetry,  rleq_functionality_wrt_implies,  r-triangle-inequality,  rabs-neq-zero,  rmul_preserves_rless,  rdiv_wf,  rless-int,  rless_wf,  rless-int-fractions2,  nat_plus_properties,  decidable__lt,  full-omega-unsat,  intformnot_wf,  intformless_wf,  itermConstant_wf,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  istype-less_than,  rmul_wf,  rinv_wf2,  itermMultiply_wf,  rless_functionality,  req_transitivity,  rinv-mul-as-rdiv,  real_term_value_mul_lemma,  small-reciprocal-real,  istype-le,  assert-rat-term-eq2,  rtermMultiply_wf,  rtermDivide_wf,  rtermConstant_wf,  rtermVar_wf,  rless_transitivity2,  nat_properties,  intformand_wf,  int_formula_prop_and_lemma,  int_term_value_var_lemma,  radd-preserves-rless,  squash_wf,  true_wf,  radd_comm_eq,  subtype_rel_self,  iff_weakening_equal,  rmul-rinv3,  radd_comm,  nat_plus_wf,  int_term_value_mul_lemma,  rneq_functionality,  rmul-int,  rneq-int,  intformeq_wf,  int_formula_prop_eq_lemma,  set_subtype_base,  less_than_wf,  int_subtype_base,  rmul_functionality,  req_inversion,  rinv_functionality2,  rinv-of-rmul,  sq-all-large-and,  rleq_wf,  rpositive-rless,  rabs-positive,  absval_wf,  rabs-rmul,  rabs-rdiv,  rabs-int,  rmul_preserves_rleq,  rinv-as-rdiv,  rmul-rinv,  rleq_weakening_rless,  rabs-rmul-rleq,  square-nonzero,  req-int-fractions,  nequal_wf,  nat_plus_inc_int_nzero,  decidable__equal_int,  req_functionality,  rmul-rdiv-cancel5,  int_entire_a,  subtype_base_sq,  rminus_functionality
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  sqequalHypSubstitution,  cut,  universeIsType,  introduction,  extract_by_obid,  isectElimination,  thin,  hypothesisEquality,  natural_numberEquality,  hypothesis,  sqequalRule,  functionIsType,  applyEquality,  lambdaEquality_alt,  because_Cache,  productElimination,  independent_isectElimination,  dependent_functionElimination,  approximateComputation,  int_eqEquality,  equalityTransitivity,  equalitySymmetry,  isect_memberEquality_alt,  voidElimination,  independent_functionElimination,  closedConclusion,  inrFormation_alt,  independent_pairFormation,  imageMemberEquality,  baseClosed,  dependent_set_memberEquality_alt,  setElimination,  rename,  unionElimination,  dependent_pairFormation_alt,  inhabitedIsType,  imageElimination,  instantiate,  universeEquality,  multiplyEquality,  equalityIstype,  baseApply,  intEquality,  sqequalBase,  cumulativity

Latex:
\mforall{}x:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.  \mforall{}a:\mBbbR{}.    (lim  n\mrightarrow{}\minfty{}.x[n]  =  a  {}\mRightarrow{}  (\mforall{}n:\mBbbN{}.  x[n]  \mneq{}  r0)  {}\mRightarrow{}  a  \mneq{}  r0  {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.(r1/x[n])  =  (r1/a))



Date html generated: 2019_10_29-AM-10_22_43
Last ObjectModification: 2019_04_02-PM-04_08_58

Theory : reals


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