Nuprl Lemma : derivative-rinv

∀I:Interval. ∀f,g:I ⟶ℝ.
  ((∀x,y:{t:ℝ| t ∈ I} .  ((x = y) ⇒ (g[x] = g[y])))
  ⇒ f[x]≠r0 for x ∈ I
  ⇒ d(f[x])/dx = λx.g[x] on I
  ⇒ d((r1/f[x]))/dx = λx.(-(g[x])/f[x] * f[x]) on I)


Proof




Definitions occuring in Statement :  derivative: d(f[x])/dx = λz.g[z] on I,  nonzero-on: f[x]≠r0 for x ∈ I,  rfun: I ⟶ℝ,  i-member: r ∈ I,  interval: Interval,  rdiv: (x/y),  req: x = y,  rmul: a * b,  rminus: -(x),  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: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  derivative: d(f[x])/dx = λz.g[z] on I,  member: t ∈ T,  nat_plus: ℕ+,  uall: ∀[x:A]. B[x],  nonzero-on: f[x]≠r0 for x ∈ I,  and: P ∧ Q,  prop: ℙ,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  so_lambda: λ2x.t[x],  rfun: I ⟶ℝ,  so_apply: x[s],  sq_stable: SqStable(P),  squash: ↓T,  subinterval: I ⊆ J ,  rneq: x ≠ y,  label: ...$L... t,  guard: {T},  exists: ∃x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  top: Top,  cand: A c∧ B,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  rge: x ≥ y,  less_than: a < b,  less_than': less_than'(a;b),  true: True,  sq_exists: ∃x:A [B[x]],  continuous: f[x] continuous for x ∈ I,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  rless: x < y,  int_nzero: ℤ-o,  nequal: a ≠ b ∈ T ,  sq_type: SQType(T),  req_int_terms: t1 ≡ t2,  rdiv: (x/y)
Lemmas referenced :  i-approx-is-subinterval,  istype-less_than,  nonzero-on-implies,  icompact_wf,  i-approx_wf,  continuous-implies-functional,  rfun_subtype,  proper-continuous-implies,  differentiable-continuous,  sq_stable__icompact,  sq_stable__iproper,  function-is-continuous,  rdiv_wf,  int-to-real_wf,  subtype_rel_sets_simple,  real_wf,  i-member_wf,  sq_stable__i-member,  req_wf,  i-member-approx,  iproper_wf,  nat_plus_wf,  derivative_wf,  nonzero-on_wf,  rfun_wf,  interval_wf,  req_weakening,  rdiv_functionality,  Inorm-bound,  Inorm_wf,  rleq_wf,  rabs_wf,  imax_wf,  r-bound_wf,  imax_nat_plus,  nat_plus_properties,  decidable__lt,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  intformeq_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_eq_lemma,  int_formula_prop_wf,  rmax_wf,  rmax_ub,  rleq_functionality,  req_inversion,  rmax-int,  r-bound-property,  rleq_functionality_wrt_implies,  rleq_weakening_equal,  mul_nat_plus,  i-approx-approx,  rmin_wf,  rsub_wf,  rless_wf,  rmul_wf,  rminus_wf,  rless-int,  rmin_strict_ub,  rmin-rleq,  implies_weakening_uimplies,  rneq-int,  int_entire_a,  mul_nzero,  subtype_base_sq,  int_subtype_base,  nequal_wf,  rneq_wf,  rmul_reverses_rless,  rmul_preserves_rless,  squash_wf,  true_wf,  rabs-rminus,  subtype_rel_self,  iff_weakening_equal,  itermSubtract_wf,  itermMultiply_wf,  radd_wf,  rinv_wf2,  itermMinus_wf,  itermAdd_wf,  rless_functionality,  req-iff-rsub-is-0,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_const_lemma,  real_term_value_var_lemma,  uiff_transitivity,  req_functionality,  rmul_functionality,  rabs-rmul,  req_transitivity,  rabs_functionality,  rminus_functionality,  rsub_functionality,  rinv-of-rmul,  radd_functionality,  rinv-mul-as-rdiv,  rinv-as-rdiv,  rmul-rinv3,  rmul-rinv,  real_term_value_minus_lemma,  real_term_value_add_lemma,  rmul-nonneg-case1,  zero-rleq-rabs,  rmul_functionality_wrt_rleq2,  rleq-int,  decidable__le,  intformle_wf,  int_formula_prop_le_lemma,  rmul_preserves_rleq2,  rmul-identity1,  rmul-int,  uimplies_transitivity,  rleq_transitivity,  r-triangle-inequality,  rleq_weakening,  multiply_nat_plus,  int_term_value_mul_lemma,  radd_functionality_wrt_rleq,  rabs-difference-symmetry,  rabs-rmul-rleq,  rleq-int-fractions,  rmul-int-rdiv,  mul_bounds_1a,  nat_plus_subtype_nat,  rneq_functionality,  set_subtype_base,  less_than_wf,  rinv_functionality2,  rmul_preserves_rleq,  square-nonzero
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  because_Cache,  dependent_set_memberEquality_alt,  setElimination,  rename,  hypothesisEquality,  hypothesis,  isectElimination,  natural_numberEquality,  independent_functionElimination,  productElimination,  universeIsType,  applyEquality,  independent_isectElimination,  sqequalRule,  lambdaEquality_alt,  imageMemberEquality,  baseClosed,  imageElimination,  closedConclusion,  setIsType,  promote_hyp,  inhabitedIsType,  productIsType,  functionIsType,  dependent_pairFormation_alt,  equalityTransitivity,  equalitySymmetry,  isectIsType,  applyLambdaEquality,  unionElimination,  approximateComputation,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  independent_pairFormation,  equalityIsType1,  inlFormation_alt,  inrFormation_alt,  dependent_set_memberFormation_alt,  multiplyEquality,  instantiate,  cumulativity,  intEquality,  equalityIsType4,  universeEquality,  baseApply

Latex:
\mforall{}I:Interval.  \mforall{}f,g:I  {}\mrightarrow{}\mBbbR{}.
    ((\mforall{}x,y:\{t:\mBbbR{}|  t  \mmember{}  I\}  .    ((x  =  y)  {}\mRightarrow{}  (g[x]  =  g[y])))
    {}\mRightarrow{}  f[x]\mneq{}r0  for  x  \mmember{}  I
    {}\mRightarrow{}  d(f[x])/dx  =  \mlambda{}x.g[x]  on  I
    {}\mRightarrow{}  d((r1/f[x]))/dx  =  \mlambda{}x.(-(g[x])/f[x]  *  f[x])  on  I)



Date html generated: 2019_10_30-AM-09_02_57
Last ObjectModification: 2018_11_12-AM-11_59_54

Theory : reals


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