Nuprl Lemma : compact-proper-interval-near-member
∀J:Interval
  (icompact(J)
  ⇒ iproper(J)
  ⇒ (∀x:ℝ. ((x ∈ J) ⇒ (∀r:ℝ. ((r0 < r) ⇒ (∃y:ℝ. ((y ∈ J) ∧ (|y - x| ≤ r) ∧ (r0 < |y - x|))))))))
Proof
Definitions occuring in Statement : 
icompact: icompact(I), 
i-member: r ∈ I, 
iproper: iproper(I), 
interval: Interval, 
rleq: x ≤ y, 
rless: x < y, 
rabs: |x|, 
rsub: x - y, 
int-to-real: r(n), 
real: ℝ, 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
implies: P ⇒ Q, 
and: P ∧ Q, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
interval: Interval, 
iproper: iproper(I), 
icompact: icompact(I), 
i-finite: i-finite(I), 
i-closed: i-closed(I), 
i-nonvoid: i-nonvoid(I), 
isl: isl(x), 
outl: outl(x), 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
btrue: tt, 
assert: ↑b, 
bor: p ∨bq, 
bfalse: ff, 
i-member: r ∈ I, 
right-endpoint: right-endpoint(I), 
left-endpoint: left-endpoint(I), 
endpoints: endpoints(I), 
pi1: fst(t), 
pi2: snd(t), 
implies: P ⇒ Q, 
and: P ∧ Q, 
cand: A c∧ B, 
true: True, 
member: t ∈ T, 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
exists: ∃x:A. B[x], 
false: False, 
or: P ∨ Q, 
iff: P ⇐⇒ Q, 
uimplies: b supposing a, 
itermConstant: "const", 
req_int_terms: t1 ≡ t2, 
not: ¬A, 
top: Top, 
uiff: uiff(P;Q), 
squash: ↓T, 
subtype_rel: A ⊆r B, 
guard: {T}, 
rev_implies: P ⇐ Q, 
rev_uimplies: rev_uimplies(P;Q), 
rge: x ≥ y, 
rsub: x - y
Lemmas referenced : 
rless_wf, 
int-to-real_wf, 
real_wf, 
rleq_wf, 
true_wf, 
exists_wf, 
false_wf, 
interval_wf, 
rless-cases, 
rmin_strict_ub, 
rsub_wf, 
rless-implies-rless, 
real_term_polynomial, 
itermSubtract_wf, 
itermVar_wf, 
itermConstant_wf, 
real_term_value_const_lemma, 
real_term_value_sub_lemma, 
real_term_value_var_lemma, 
req-iff-rsub-is-0, 
itermMinus_wf, 
rmin_wf, 
real_term_value_minus_lemma, 
rminus_wf, 
rabs_wf, 
squash_wf, 
rabs-rminus, 
iff_weakening_equal, 
rmin-rleq, 
rleq_weakening_rless, 
rleq_functionality, 
rabs_functionality, 
req_weakening, 
rless_functionality, 
rabs-of-nonneg, 
radd-preserves-rleq, 
radd_wf, 
itermAdd_wf, 
real_term_value_add_lemma, 
rmin_functionality, 
rleq_weakening_equal, 
rleq_functionality_wrt_implies, 
trivial-rsub-rleq, 
rmul_wf, 
uiff_transitivity, 
req_transitivity, 
radd_functionality, 
rminus-as-rmul, 
req_inversion, 
rmul-identity1, 
rmul-distrib2, 
radd-assoc, 
rmul_functionality, 
radd-int, 
rmul-zero-both, 
radd-zero-both
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
unionElimination, 
sqequalRule, 
rename, 
cut, 
hypothesis, 
independent_functionElimination, 
natural_numberEquality, 
independent_pairFormation, 
because_Cache, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
productEquality, 
functionEquality, 
lambdaEquality, 
voidElimination, 
dependent_functionElimination, 
independent_isectElimination, 
computeAll, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidEquality, 
dependent_pairFormation, 
addLevel, 
applyEquality, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
addEquality, 
minusEquality, 
lemma_by_obid
Latex:
\mforall{}J:Interval
    (icompact(J)
    {}\mRightarrow{}  iproper(J)
    {}\mRightarrow{}  (\mforall{}x:\mBbbR{}.  ((x  \mmember{}  J)  {}\mRightarrow{}  (\mforall{}r:\mBbbR{}.  ((r0  <  r)  {}\mRightarrow{}  (\mexists{}y:\mBbbR{}.  ((y  \mmember{}  J)  \mwedge{}  (|y  -  x|  \mleq{}  r)  \mwedge{}  (r0  <  |y  -  x|))))))))
Date html generated:
2017_10_03-AM-09_35_11
Last ObjectModification:
2017_07_28-AM-07_52_47
Theory : reals
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