Nuprl Lemma : derivative-log-contraction-bound
∀a:{a:ℝ| r0 < a} . ∀[x:ℝ]. (|(a - e^x/a + e^x)^2| ≤ r1)
Proof
Definitions occuring in Statement : 
rexp: e^x
, 
rdiv: (x/y)
, 
rleq: x ≤ y
, 
rless: x < y
, 
rabs: |x|
, 
rnexp: x^k1
, 
rsub: x - y
, 
radd: a + b
, 
int-to-real: r(n)
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
set: {x:A| B[x]} 
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
le: A ≤ B
, 
and: P ∧ Q
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
false: False
, 
nat: ℕ
, 
less_than': less_than'(a;b)
, 
prop: ℙ
, 
uimplies: b supposing a
, 
rneq: x ≠ y
, 
guard: {T}
, 
or: P ∨ Q
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
rev_implies: P 
⇐ Q
, 
rge: x ≥ y
, 
rgt: x > y
, 
iff: P 
⇐⇒ Q
, 
exp: i^n
, 
primrec: primrec(n;b;c)
, 
subtract: n - m
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
, 
cand: A c∧ B
, 
rsub: x - y
, 
less_than: a < b
, 
true: True
Lemmas referenced : 
real_wf, 
less_than'_wf, 
rsub_wf, 
int-to-real_wf, 
rabs_wf, 
rnexp_wf, 
false_wf, 
le_wf, 
rdiv_wf, 
rexp_wf, 
radd_wf, 
rless_wf, 
nat_plus_wf, 
set_wf, 
sq_stable__rless, 
rless_functionality_wrt_implies, 
rleq_weakening_equal, 
rleq_weakening_rless, 
radd_functionality_wrt_rless1, 
rexp-positive, 
rless_functionality, 
req_weakening, 
radd-zero-both, 
radd_comm, 
rnexp-rleq, 
zero-rleq-rabs, 
exp_wf2, 
rleq-int, 
rleq_functionality, 
rabs-rnexp, 
rleq_functionality_wrt_implies, 
rnexp-int, 
rabs-of-nonneg, 
req_inversion, 
rless_transitivity1, 
rleq_weakening, 
rabs-rdiv, 
rabs-difference-bound-rleq, 
rleq_wf, 
rmul_wf, 
rminus_wf, 
radd-preserves-rleq, 
uiff_transitivity, 
radd_functionality, 
rminus-radd, 
req_transitivity, 
radd-assoc, 
rmul-identity1, 
rmul-distrib2, 
rminus-as-rmul, 
rmul_functionality, 
radd-int, 
rmul-zero-both, 
rmul_preserves_rleq, 
rless-int, 
rmul-nonneg-case1, 
rmul-int, 
rmul-assoc, 
rmul_comm, 
radd-ac, 
radd-rminus-both, 
rdiv_functionality, 
rmul-rdiv-cancel2, 
rmul-distrib, 
rmul-one-both, 
rabs_functionality
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
hypothesis, 
isect_memberFormation, 
sqequalRule, 
sqequalHypSubstitution, 
lambdaEquality, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
productElimination, 
independent_pairEquality, 
voidElimination, 
isectElimination, 
applyEquality, 
natural_numberEquality, 
dependent_set_memberEquality, 
independent_pairFormation, 
setElimination, 
rename, 
because_Cache, 
independent_isectElimination, 
inrFormation, 
minusEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
addLevel, 
addEquality, 
multiplyEquality
Latex:
\mforall{}a:\{a:\mBbbR{}|  r0  <  a\}  .  \mforall{}[x:\mBbbR{}].  (|(a  -  e\^{}x/a  +  e\^{}x)\^{}2|  \mleq{}  r1)
Date html generated:
2016_10_26-PM-00_30_24
Last ObjectModification:
2016_09_19-AM-10_01_16
Theory : reals_2
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