Nuprl Lemma : i-finite-iff-bounded
∀I:Interval. (i-finite(I) 
⇐⇒ ∃a,b:ℝ. ∀[r:ℝ]. a≤r≤b supposing r ∈ I)
Proof
Definitions occuring in Statement : 
i-member: r ∈ I
, 
i-finite: i-finite(I)
, 
interval: Interval
, 
rbetween: x≤y≤z
, 
real: ℝ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
iff: P 
⇐⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
rev_implies: P 
⇐ Q
, 
so_lambda: λ2x.t[x]
, 
uimplies: b supposing a
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
rbetween: x≤y≤z
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
le: A ≤ B
, 
not: ¬A
, 
false: False
, 
subtype_rel: A ⊆r B
, 
real: ℝ
, 
uiff: uiff(P;Q)
, 
less_than: a < b
, 
squash: ↓T
, 
less_than': less_than'(a;b)
, 
true: True
, 
guard: {T}
, 
rsub: x - y
, 
interval: Interval
, 
i-finite: i-finite(I)
, 
isl: isl(x)
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
cand: A c∧ B
, 
bfalse: ff
, 
i-member: r ∈ I
, 
rge: x ≥ y
, 
or: P ∨ Q
Lemmas referenced : 
i-finite_wf, 
exists_wf, 
real_wf, 
uall_wf, 
isect_wf, 
i-member_wf, 
rbetween_wf, 
interval_wf, 
left-endpoint_wf, 
right-endpoint_wf, 
less_than'_wf, 
rsub_wf, 
nat_plus_wf, 
i-member-finite, 
rleq_wf, 
radd_wf, 
int-to-real_wf, 
radd-preserves-rleq, 
rminus_wf, 
rmul_wf, 
uiff_transitivity, 
rleq_functionality, 
req_transitivity, 
radd_functionality, 
req_weakening, 
rminus-as-rmul, 
radd-assoc, 
req_inversion, 
rmul-identity1, 
rmul-distrib2, 
rmul_functionality, 
radd-int, 
rmul-zero-both, 
radd-zero-both, 
rless-int, 
rless_transitivity1, 
rless_irreflexivity, 
uiff_transitivity2, 
radd-ac, 
radd_comm, 
radd-rminus-both, 
squash_wf, 
true_wf, 
rminus-int, 
rmax_wf, 
rleq-rmax, 
rmax_lb, 
trivial-rless-radd, 
rless_functionality_wrt_implies, 
rleq_weakening_equal, 
rmin_wf, 
rmin-rleq, 
rmin_ub, 
rmin_strict_lb, 
trivial-rsub-rless, 
rless_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
independent_pairFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
dependent_pairFormation, 
independent_isectElimination, 
isect_memberFormation, 
productElimination, 
independent_pairEquality, 
dependent_functionElimination, 
because_Cache, 
applyEquality, 
setElimination, 
rename, 
minusEquality, 
natural_numberEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
voidElimination, 
addEquality, 
independent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
unionElimination, 
inlFormation
Latex:
\mforall{}I:Interval.  (i-finite(I)  \mLeftarrow{}{}\mRightarrow{}  \mexists{}a,b:\mBbbR{}.  \mforall{}[r:\mBbbR{}].  a\mleq{}r\mleq{}b  supposing  r  \mmember{}  I)
Date html generated:
2016_10_26-AM-09_29_03
Last ObjectModification:
2016_09_11-PM-07_52_21
Theory : reals
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