Nuprl Lemma : compact-subinterval
∀I:Interval. ∀J:{J:Interval| icompact(J)} .  (J ⊆ I  
⇒ (∃n:{n:ℕ+| icompact(i-approx(I;n))} . J ⊆ i-approx(I;n) ))
Proof
Definitions occuring in Statement : 
subinterval: I ⊆ J 
, 
icompact: icompact(I)
, 
i-approx: i-approx(I;n)
, 
interval: Interval
, 
nat_plus: ℕ+
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
set: {x:A| B[x]} 
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
iff: P 
⇐⇒ Q
, 
exists: ∃x:A. B[x]
, 
guard: {T}
, 
icompact: icompact(I)
, 
subinterval: I ⊆ J 
, 
nat_plus: ℕ+
, 
rev_implies: P 
⇐ Q
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
not: ¬A
, 
top: Top
, 
cand: A c∧ B
, 
i-nonvoid: i-nonvoid(I)
, 
rbetween: x≤y≤z
Lemmas referenced : 
sq_stable__icompact, 
i-member-compact, 
icompact-endpoints, 
i-member-iff, 
subinterval_wf, 
set_wf, 
interval_wf, 
icompact_wf, 
left-endpoint_wf, 
right-endpoint_wf, 
i-approx_wf, 
less_than_wf, 
imax_wf, 
imax_nat_plus, 
nat_plus_wf, 
nat_plus_properties, 
decidable__lt, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformless_wf, 
itermConstant_wf, 
itermVar_wf, 
intformeq_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_eq_lemma, 
int_formula_prop_wf, 
equal_wf, 
i-approx-closed, 
i-approx-finite, 
i-member_wf, 
i-approx-monotonic, 
imax_ub, 
decidable__le, 
intformle_wf, 
int_formula_prop_le_lemma, 
le_wf, 
real_wf, 
i-member-between
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
setElimination, 
thin, 
rename, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
because_Cache, 
isectElimination, 
lambdaEquality, 
productElimination, 
independent_isectElimination, 
dependent_pairFormation, 
dependent_set_memberEquality, 
natural_numberEquality, 
equalityTransitivity, 
equalitySymmetry, 
applyLambdaEquality, 
unionElimination, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
computeAll, 
inrFormation, 
inlFormation
Latex:
\mforall{}I:Interval.  \mforall{}J:\{J:Interval|  icompact(J)\}  .
    (J  \msubseteq{}  I    {}\mRightarrow{}  (\mexists{}n:\{n:\mBbbN{}\msupplus{}|  icompact(i-approx(I;n))\}  .  J  \msubseteq{}  i-approx(I;n)  ))
Date html generated:
2017_10_03-AM-09_34_55
Last ObjectModification:
2017_07_28-AM-07_52_37
Theory : reals
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