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:ℝx ∈ 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: so_apply: x[s] all: x:A. B[x] implies:  Q set: {x:A| B[x]}  natural_number: $n
Definitions unfolded in proof :  increasing-on-interval: f[x] increasing for x ∈ I sq_type: SQType(T) nequal: a ≠ b ∈  int_nzero: -o rgt: x > y rdiv: (x/y) req_int_terms: t1 ≡ t2 uiff: uiff(P;Q) rge: x ≥ y rev_uimplies: rev_uimplies(P;Q) subinterval: I ⊆  i-member: r ∈ I subtype_rel: A ⊆B le: A ≤ B rnonneg: rnonneg(x) rleq: x ≤ y top: Top false: False satisfiable_int_formula: satisfiable_int_formula(fmla) not: ¬A decidable: Dec(P) rless: x < y or: P ∨ Q rneq: x ≠ y sq_exists: x:A [B[x]] uimplies: supposing a true: True less_than': less_than'(a;b) less_than: a < b nat_plus: + rccint: [l, u] i-approx: i-approx(I;n) continuous: f[x] continuous for x ∈ I guard: {T} exists: x:A. B[x] label: ...$L... t rfun: I ⟶ℝ so_apply: x[s] so_lambda: λ2x.t[x] uall: [x:A]. B[x] prop: squash: T sq_stable: SqStable(P) cand: c∧ B rev_implies:  Q and: P ∧ Q iff: ⇐⇒ Q member: t ∈ T strictly-increasing-on-interval: f[x] strictly-increasing for x ∈ I implies:  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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