Nuprl Lemma : continuous-limit

∀I:Interval. ∀f:I ⟶ℝ. ∀y:ℝ. ∀x:ℕ ⟶ ℝ.
  (f(x) continuous for x ∈ I ⇒ lim n→∞.x[n] = y ⇒ (y ∈ I) ⇒ (∀n:ℕ. (x[n] ∈ I)) ⇒ lim n→∞.f(x[n]) = f(y))


Proof




Definitions occuring in Statement :  continuous: f[x] continuous for x ∈ I,  r-ap: f(x),  rfun: I ⟶ℝ,  i-member: r ∈ I,  interval: Interval,  converges-to: lim n→∞.x[n] = y,  real: ℝ,  nat: ℕ,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  function: x:A ⟶ B[x]
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  converges-to: lim n→∞.x[n] = y,  member: t ∈ T,  iff: P ⇐⇒ Q,  and: P ∧ Q,  exists: ∃x:A. B[x],  uall: ∀[x:A]. B[x],  nat_plus: ℕ+,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  true: True,  prop: ℙ,  uimplies: b supposing a,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  not: ¬A,  top: Top,  continuous: f[x] continuous for x ∈ I,  sq_exists: ∃x:{A| B[x]},  so_lambda: λ2x.t[x],  so_apply: x[s],  label: ...$L... t,  rfun: I ⟶ℝ,  sq_stable: SqStable(P),  nat: ℕ,  rneq: x ≠ y,  guard: {T},  rev_implies: P ⇐ Q,  rless: x < y,  ge: i ≥ j ,  subtype_rel: A ⊆r B,  real: ℝ,  cand: A c∧ B,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  interval: Interval,  i-approx: i-approx(I;n),  i-member: r ∈ I,  rccint: [l, u],  rge: x ≥ y,  rsub: x - y
Lemmas referenced :  i-member-iff,  i-approx-monotonic,  mul_nat_plus,  less_than_wf,  nat_plus_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermVar_wf,  itermMultiply_wf,  itermConstant_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_var_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  i-approx-compact,  icompact_wf,  i-approx_wf,  nat_plus_wf,  all_wf,  nat_wf,  i-member_wf,  converges-to_wf,  continuous_wf,  r-ap_wf,  sq_stable__i-member,  real_wf,  rfun_wf,  interval_wf,  sq_stable__rless,  int-to-real_wf,  le_wf,  rleq_wf,  rabs_wf,  rsub_wf,  rdiv_wf,  rless-int,  nat_properties,  decidable__lt,  rless_wf,  small-reciprocal-real,  rless_transitivity2,  rleq_weakening_rless,  imax_wf,  imax_nat,  sq_stable__less_than,  intformeq_wf,  int_formula_prop_eq_lemma,  equal_wf,  imax_lb,  rabs-difference-bound-rleq,  radd_wf,  multiply_nat_plus,  req-int-fractions,  decidable__equal_int,  itermAdd_wf,  int_term_value_add_lemma,  req_functionality,  radd-int-fractions,  req_weakening,  rleq-int-fractions,  req-int-fractions2,  rleq_functionality,  req_wf,  true_wf,  rmul_wf,  rminus_wf,  rleq_weakening_equal,  rleq_functionality_wrt_implies,  rleq_transitivity,  rsub_functionality_wrt_rleq,  rleq_weakening,  req_inversion,  radd_functionality,  uiff_transitivity,  rsub_functionality,  req_transitivity,  rmul-identity1,  rmul-distrib2,  rmul_functionality,  radd-int,  radd-assoc,  radd_comm,  radd-ac,  rminus-as-rmul,  rmul-one-both,  radd_functionality_wrt_rleq,  radd-preserves-rleq,  rminus-radd,  radd-rminus-assoc,  rmul-zero-both,  radd-zero-both,  rleq-int,  uimplies_transitivity,  subtract_wf,  itermMinus_wf,  itermSubtract_wf,  int_term_value_minus_lemma,  int_term_value_subtract_lemma,  rsub-int
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  hypothesis,  addLevel,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  productElimination,  independent_functionElimination,  isectElimination,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  independent_pairFormation,  imageMemberEquality,  baseClosed,  independent_isectElimination,  setElimination,  rename,  multiplyEquality,  unionElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  because_Cache,  levelHypothesis,  applyEquality,  functionExtensionality,  imageElimination,  setEquality,  functionEquality,  inrFormation,  dependent_set_memberFormation,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  addEquality,  productEquality,  minusEquality

Latex:
\mforall{}I:Interval.  \mforall{}f:I  {}\mrightarrow{}\mBbbR{}.  \mforall{}y:\mBbbR{}.  \mforall{}x:\mBbbN{}  {}\mrightarrow{}  \mBbbR{}.
    (f(x)  continuous  for  x  \mmember{}  I
    {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.x[n]  =  y
    {}\mRightarrow{}  (y  \mmember{}  I)
    {}\mRightarrow{}  (\mforall{}n:\mBbbN{}.  (x[n]  \mmember{}  I))
    {}\mRightarrow{}  lim  n\mrightarrow{}\minfty{}.f(x[n])  =  f(y))



Date html generated: 2017_10_03-AM-10_18_54
Last ObjectModification: 2017_07_28-AM-08_06_13

Theory : reals


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