Nuprl Lemma : derivative-continuous
∀I:Interval. ∀f,g:I ⟶ℝ.
  ((∀x,y:{x:ℝ| x ∈ I} .  (g[x] ≠ g[y] 
⇒ x ≠ y)) 
⇒ λx.g[x] = d(f[x])/dx on I 
⇒ g[x] continuous for x ∈ I)
Proof
Definitions occuring in Statement : 
derivative: λz.g[z] = d(f[x])/dx on I
, 
continuous: f[x] continuous for x ∈ I
, 
rfun: I ⟶ℝ
, 
i-member: r ∈ I
, 
interval: Interval
, 
rneq: x ≠ y
, 
real: ℝ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
rfun: I ⟶ℝ
, 
label: ...$L... t
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
member: t ∈ T
, 
continuous: f[x] continuous for x ∈ I
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
top: Top
, 
not: ¬A
, 
false: False
, 
exists: ∃x:A. B[x]
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
decidable: Dec(P)
, 
rless: x < y
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
or: P ∨ Q
, 
guard: {T}
, 
rneq: x ≠ y
, 
uimplies: b supposing a
, 
cand: A c∧ B
, 
sq_exists: ∃x:{A| B[x]}
, 
and: P ∧ Q
, 
true: True
, 
less_than': less_than'(a;b)
, 
squash: ↓T
, 
less_than: a < b
, 
nat_plus: ℕ+
, 
derivative: λz.g[z] = d(f[x])/dx on I
, 
subinterval: I ⊆ J 
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
rge: x ≥ y
, 
rsub: x - y
, 
rgt: x > y
Lemmas referenced : 
rmul_comm, 
rless_functionality, 
rmul_preserves_rless, 
rless_transitivity1, 
rneq-int, 
equal_wf, 
rless_irreflexivity, 
rleq_weakening_rless, 
rless_functionality_wrt_implies, 
rless-int-fractions2, 
rneq-iff-rabs, 
rleq-iff-not-rless, 
rminus-as-rmul, 
radd-rminus-assoc, 
radd_comm, 
radd-ac, 
radd-assoc, 
rminus-rminus, 
rminus-radd, 
rminus_functionality, 
rmul_over_rminus, 
radd_functionality, 
rmul-distrib, 
req_transitivity, 
rabs_functionality, 
uiff_transitivity, 
rabs-rmul, 
rminus_wf, 
r-triangle-inequality, 
radd-int-fractions, 
req_functionality, 
multiply_nat_plus, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
req-int-fractions, 
decidable__equal_int, 
itermAdd_wf, 
int_term_value_add_lemma, 
rmul-distrib2, 
req_inversion, 
rleq_weakening_equal, 
radd_functionality_wrt_rleq, 
rleq_functionality_wrt_implies, 
radd_wf, 
rmul_functionality, 
rmul_wf, 
itermMultiply_wf, 
int_term_value_mul_lemma, 
req_weakening, 
rabs-difference-symmetry, 
rleq_functionality, 
i-approx-is-subinterval, 
mul_nat_plus, 
less_than_wf, 
rleq_wf, 
rabs_wf, 
rsub_wf, 
rless_wf, 
int-to-real_wf, 
rdiv_wf, 
rless-int, 
nat_plus_properties, 
decidable__lt, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermConstant_wf, 
itermVar_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, 
nat_plus_wf, 
set_wf, 
icompact_wf, 
i-approx_wf, 
derivative_wf, 
real_wf, 
i-member_wf, 
all_wf, 
rneq_wf, 
rfun_wf, 
interval_wf
Rules used in proof : 
dependent_set_memberEquality, 
functionEquality, 
rename, 
setElimination, 
because_Cache, 
setEquality, 
applyEquality, 
hypothesisEquality, 
lambdaEquality, 
sqequalRule, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
hypothesis, 
lemma_by_obid, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
computeAll, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
intEquality, 
int_eqEquality, 
dependent_pairFormation, 
unionElimination, 
independent_functionElimination, 
inrFormation, 
independent_isectElimination, 
productEquality, 
productElimination, 
baseClosed, 
imageMemberEquality, 
introduction, 
independent_pairFormation, 
natural_numberEquality, 
dependent_functionElimination, 
multiplyEquality, 
equalityTransitivity, 
equalitySymmetry, 
equalityEquality, 
addEquality, 
minusEquality, 
inlFormation
Latex:
\mforall{}I:Interval.  \mforall{}f,g:I  {}\mrightarrow{}\mBbbR{}.
    ((\mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  I\}  .    (g[x]  \mneq{}  g[y]  {}\mRightarrow{}  x  \mneq{}  y))
    {}\mRightarrow{}  \mlambda{}x.g[x]  =  d(f[x])/dx  on  I
    {}\mRightarrow{}  g[x]  continuous  for  x  \mmember{}  I)
Date html generated:
2016_05_18-AM-10_00_54
Last ObjectModification:
2016_01_17-AM-00_44_47
Theory : reals
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