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
Home
Index