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: so_apply: x[s] all: x:A. B[x] implies:  Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  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: ⇐⇒ Q guard: {T} uimplies: supposing a uall: [x:A]. B[x] prop: 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: + rev_implies:  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 ⊆B squash: T rdiv: (x/y) nequal: a ≠ b ∈  int_nzero: -o cand: c∧ B rsub: 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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