Nuprl Lemma : continuous-limit

I:Interval. ∀f:I ⟶ℝ. ∀y:ℝ. ∀x:ℕ ⟶ ℝ.
  (f(x) continuous for x ∈  lim n→∞.x[n]  (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: nat: so_apply: x[s] all: x:A. B[x] implies:  Q function: x:A ⟶ B[x]
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q converges-to: lim n→∞.x[n] y member: t ∈ T iff: ⇐⇒ Q and: P ∧ Q exists: x:A. B[x] uall: [x:A]. B[x] nat_plus: + less_than: a < b squash: T less_than': less_than'(a;b) true: True prop: uimplies: 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: rneq: x ≠ y guard: {T} rev_implies:  Q rless: x < y ge: i ≥  subtype_rel: A ⊆B real: cand: 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: 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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