Nuprl Lemma : derivative-implies-strictly-increasing

∀I:Interval
  (iproper(I)
  ⇒ (∀f,f':I ⟶ℝ.
        (d(f[x])/dx = λx.f'[x] on I
        ⇒ f'[x] continuous for x ∈ I
        ⇒ (∀x:{x:ℝ| x ∈ I} . (r0 < f'[x]))
        ⇒ f[x] strictly-increasing for x ∈ I)))


Proof




Definitions occuring in Statement :  strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I,  derivative: d(f[x])/dx = λz.g[z] on I,  continuous: f[x] continuous for x ∈ I,  rfun: I ⟶ℝ,  i-member: r ∈ I,  iproper: iproper(I),  interval: Interval,  rless: x < y,  int-to-real: r(n),  real: ℝ,  so_apply: x[s],  all: ∀x:A. B[x],  implies: P ⇒ Q,  set: {x:A| B[x]} ,  natural_number: $n
Definitions unfolded in proof :  increasing-on-interval: f[x] increasing for x ∈ I,  sq_type: SQType(T),  nequal: a ≠ b ∈ T ,  int_nzero: ℤ-o,  rgt: x > y,  rdiv: (x/y),  req_int_terms: t1 ≡ t2,  uiff: uiff(P;Q),  rge: x ≥ y,  rev_uimplies: rev_uimplies(P;Q),  subinterval: I ⊆ J ,  i-member: r ∈ I,  subtype_rel: A ⊆r B,  le: A ≤ B,  rnonneg: rnonneg(x),  rleq: x ≤ y,  top: Top,  false: False,  satisfiable_int_formula: satisfiable_int_formula(fmla),  not: ¬A,  decidable: Dec(P),  rless: x < y,  or: P ∨ Q,  rneq: x ≠ y,  sq_exists: ∃x:A [B[x]],  uimplies: b supposing a,  true: True,  less_than': less_than'(a;b),  less_than: a < b,  nat_plus: ℕ+,  rccint: [l, u],  i-approx: i-approx(I;n),  continuous: f[x] continuous for x ∈ I,  guard: {T},  exists: ∃x:A. B[x],  label: ...$L... t,  rfun: I ⟶ℝ,  so_apply: x[s],  so_lambda: λ2x.t[x],  uall: ∀[x:A]. B[x],  prop: ℙ,  squash: ↓T,  sq_stable: SqStable(P),  cand: A c∧ B,  rev_implies: P ⇐ Q,  and: P ∧ Q,  iff: P ⇐⇒ Q,  member: t ∈ T,  strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I,  implies: P ⇒ Q,  all: ∀x:A. B[x]
Lemmas referenced :  i-member-between,  iff_weakening_equal,  subtype_rel_self,  rleq-implies-rleq,  trivial-rleq-radd,  derivative-implies-increasing,  rless_transitivity1,  req_functionality,  rmul_preserves_req,  rsub_functionality,  rdiv_functionality,  rinv-mul-as-rdiv,  rless_functionality_wrt_implies,  rless-int-fractions,  radd-zero,  radd-preserves-rless,  int-rinv-cancel,  rless-implies-rless,  nequal_wf,  true_wf,  equal-wf-base,  int_subtype_base,  subtype_base_sq,  minus-one-mul-top,  rmul-zero-both,  rmul_preserves_rless,  derivative_functionality_wrt_subinterval,  rfun_subtype,  mean-value-theorem,  rless_functionality,  radd_comm,  rleq_transitivity,  radd-rminus-assoc,  radd-rminus-both,  rless_transitivity2,  equal_wf,  ravg_wf,  rless-cases,  ravg-between,  rmul-rinv3,  real_term_value_mul_lemma,  real_term_value_minus_lemma,  real_term_value_add_lemma,  rinv-as-rdiv,  rinv-of-rmul,  req_inversion,  rinv_functionality2,  rmul_functionality,  rminus_functionality,  radd_functionality,  req_transitivity,  rleq_functionality,  real_term_value_const_lemma,  real_term_value_var_lemma,  real_term_value_sub_lemma,  real_polynomial_null,  itermMinus_wf,  itermAdd_wf,  equal-wf-T-base,  int_formula_prop_eq_lemma,  intformeq_wf,  rneq-int,  req_weakening,  rmul-int,  rneq_functionality,  rinv_wf2,  rmul_wf,  req-iff-rsub-is-0,  itermSubtract_wf,  rminus_wf,  radd_wf,  radd-preserves-rleq,  rabs-difference-bound-rleq,  rleq_weakening,  rleq_weakening_equal,  rleq_functionality_wrt_implies,  member_rccint_lemma,  squash_wf,  nat_plus_wf,  less_than'_wf,  sq_stable__rleq,  sq_stable__all,  sq_stable__rless,  int_formula_prop_wf,  int_term_value_var_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_formula_prop_less_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermVar_wf,  itermMultiply_wf,  itermConstant_wf,  intformless_wf,  intformnot_wf,  intformand_wf,  full-omega-unsat,  decidable__lt,  nat_plus_properties,  rless-int,  rdiv_wf,  rsub_wf,  rabs_wf,  i-approx_wf,  sq_stable__and,  mul_nat_plus,  icompact_wf,  rleq_weakening_rless,  rccint-icompact,  less_than_wf,  small-reciprocal-real,  interval_wf,  iproper_wf,  rfun_wf,  derivative_wf,  continuous_wf,  int-to-real_wf,  all_wf,  i-member_wf,  real_wf,  set_wf,  rless_wf,  rccint_wf,  continuous_functionality_wrt_subinterval,  rleq_wf,  sq_stable__i-member,  rcc-subinterval
Rules used in proof :  universeEquality,  cumulativity,  instantiate,  addLevel,  promote_hyp,  productEquality,  equalitySymmetry,  equalityTransitivity,  axiomEquality,  minusEquality,  independent_pairEquality,  voidEquality,  voidElimination,  intEquality,  int_eqEquality,  dependent_pairFormation,  approximateComputation,  unionElimination,  inrFormation,  multiplyEquality,  functionEquality,  isect_memberEquality,  independent_isectElimination,  dependent_set_memberEquality,  applyEquality,  natural_numberEquality,  setEquality,  lambdaEquality,  because_Cache,  isectElimination,  independent_pairFormation,  imageElimination,  baseClosed,  imageMemberEquality,  sqequalRule,  independent_functionElimination,  productElimination,  hypothesis,  rename,  setElimination,  hypothesisEquality,  thin,  dependent_functionElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}I:Interval
    (iproper(I)
    {}\mRightarrow{}  (\mforall{}f,f':I  {}\mrightarrow{}\mBbbR{}.
                (d(f[x])/dx  =  \mlambda{}x.f'[x]  on  I
                {}\mRightarrow{}  f'[x]  continuous  for  x  \mmember{}  I
                {}\mRightarrow{}  (\mforall{}x:\{x:\mBbbR{}|  x  \mmember{}  I\}  .  (r0  <  f'[x]))
                {}\mRightarrow{}  f[x]  strictly-increasing  for  x  \mmember{}  I)))



Date html generated: 2018_05_22-PM-02_47_15
Last ObjectModification: 2018_05_21-AM-01_12_47

Theory : reals


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