Nuprl Lemma : locally-non-constant-via-rational

∀a,b,c:ℝ. ∀f:[a, b] ⟶ℝ.
  (f[x] continuous for x ∈ [a, b] ⇒ locally-non-constant(f;a;b;c) ⇒ locally-non-constant-rational(f;a;b;c))


Proof




Definitions occuring in Statement :  locally-non-constant-rational: locally-non-constant-rational(f;a;b;c),  locally-non-constant: locally-non-constant(f;a;b;c),  continuous: f[x] continuous for x ∈ I,  rfun: I ⟶ℝ,  rccint: [l, u],  real: ℝ,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  locally-non-constant: locally-non-constant(f;a;b;c),  locally-non-constant-rational: locally-non-constant-rational(f;a;b;c),  member: t ∈ T,  exists: ∃x:A. B[x],  and: P ∧ Q,  continuous: f[x] continuous for x ∈ I,  i-approx: i-approx(I;n),  rccint: [l, u],  iff: P ⇐⇒ Q,  guard: {T},  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  top: Top,  rneq: x ≠ y,  or: P ∨ Q,  so_lambda: λ2x.t[x],  label: ...$L... t,  rfun: I ⟶ℝ,  so_apply: x[s],  i-member: r ∈ I,  itermConstant: "const",  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  uiff: uiff(P;Q),  nat_plus: ℕ+,  rev_implies: P ⇐ Q,  rless: x < y,  sq_exists: ∃x:{A| B[x]},  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  sq_stable: SqStable(P),  rleq: x ≤ y,  rnonneg: rnonneg(x),  le: A ≤ B,  subtype_rel: A ⊆r B,  squash: ↓T,  rdiv: (x/y),  nequal: a ≠ b ∈ T ,  int_nzero: ℤ-o,  cand: A c∧ B,  rsub: x - y,  rgt: x > y,  rge: x ≥ y,  rev_uimplies: rev_uimplies(P;Q),  r-ap: f(x)
Lemmas referenced :  rccint-icompact,  rless_transitivity2,  rless_transitivity1,  rleq_weakening_rless,  icompact_wf,  rccint_wf,  member_rccint_lemma,  rleq_wf,  rless_wf,  locally-non-constant_wf,  continuous_wf,  i-member_wf,  real_wf,  rfun_wf,  small-reciprocal-real-ext,  rsub_wf,  r-ap_wf,  rleq_transitivity,  rless-implies-rless,  int-to-real_wf,  real_term_polynomial,  itermSubtract_wf,  itermVar_wf,  itermConstant_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_var_lemma,  req-iff-rsub-is-0,  radd-preserves-rless,  rdiv_wf,  rless-int,  nat_plus_properties,  decidable__lt,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  radd_wf,  rmul_wf,  rinv_wf2,  sq_stable__and,  all_wf,  rabs_wf,  sq_stable__rless,  sq_stable__all,  sq_stable__rleq,  less_than'_wf,  nat_plus_wf,  squash_wf,  rless_functionality,  itermAdd_wf,  itermMultiply_wf,  real_term_value_add_lemma,  real_term_value_mul_lemma,  radd_functionality,  req_weakening,  rinv-as-rdiv,  rless-cases,  exists_wf,  int_subtype_base,  equal-wf-base,  int_formula_prop_eq_lemma,  intformeq_wf,  nequal_wf,  less_than_wf,  subtype_rel_sets,  int-rdiv_wf,  rmin_wf,  rationals-dense-ext,  radd-assoc,  req_inversion,  rmin_functionality,  rminus_functionality,  radd_comm,  radd-ac,  radd-rminus-assoc,  radd-rminus-both,  req_transitivity,  radd-zero-both,  rminus_wf,  rmul-distrib2,  rmul-identity1,  rminus-as-rmul,  radd-int,  rmul_functionality,  rmul-zero-both,  rmin_strict_ub,  rleq_weakening_equal,  rleq_functionality_wrt_implies,  int-rdiv-req,  rleq_functionality,  uiff_transitivity,  radd-preserves-rleq,  rmin-rleq,  rsub_functionality,  rabs_functionality,  rabs-difference-bound-rleq,  trivial-rsub-rleq,  radd_functionality_wrt_rless2,  rleq_weakening,  radd_functionality_wrt_rleq,  radd_functionality_wrt_rless1,  rneq_wf,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  sqequalHypSubstitution,  cut,  hypothesis,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  productElimination,  sqequalRule,  dependent_set_memberEquality,  because_Cache,  introduction,  extract_by_obid,  independent_isectElimination,  isectElimination,  isect_memberEquality,  voidElimination,  voidEquality,  unionElimination,  lambdaEquality,  applyEquality,  setElimination,  rename,  setEquality,  independent_pairFormation,  natural_numberEquality,  computeAll,  int_eqEquality,  intEquality,  inrFormation,  dependent_pairFormation,  functionEquality,  productEquality,  independent_pairEquality,  minusEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  baseClosed,  imageElimination,  promote_hyp,  applyLambdaEquality,  levelHypothesis,  addLevel,  addEquality,  inlFormation

Latex:
\mforall{}a,b,c:\mBbbR{}.  \mforall{}f:[a,  b]  {}\mrightarrow{}\mBbbR{}.
    (f[x]  continuous  for  x  \mmember{}  [a,  b]
    {}\mRightarrow{}  locally-non-constant(f;a;b;c)
    {}\mRightarrow{}  locally-non-constant-rational(f;a;b;c))



Date html generated: 2017_10_03-AM-10_30_55
Last ObjectModification: 2017_07_28-AM-08_12_12

Theory : reals


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