Nuprl Lemma : inf-rleq
∀[A:Set(ℝ)]. ∀b,c:ℝ.  (inf(A) = b 
⇒ (b ≤ c 
⇐⇒ ∀e:ℝ. ((r0 < e) 
⇒ (∃x:ℝ. ((x ∈ A) ∧ ((x - e) ≤ c))))))
Proof
Definitions occuring in Statement : 
inf: inf(A) = b
, 
rset-member: x ∈ A
, 
rset: Set(ℝ)
, 
rleq: x ≤ y
, 
rless: x < y
, 
rsub: x - y
, 
int-to-real: r(n)
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
inf: inf(A) = b
, 
member: t ∈ T
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
le: A ≤ B
, 
uimplies: b supposing a
, 
exists: ∃x:A. B[x]
, 
cand: A c∧ B
, 
uiff: uiff(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
, 
guard: {T}
, 
rev_uimplies: rev_uimplies(P;Q)
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
lower-bound: lower-bound(A;b)
, 
rge: x ≥ y
Lemmas referenced : 
rless_wf, 
int-to-real_wf, 
rleq_wf, 
le_witness_for_triv, 
rset-member_wf, 
rsub_wf, 
inf_wf, 
real_wf, 
rset_wf, 
radd-preserves-rless, 
radd_wf, 
rminus_wf, 
itermSubtract_wf, 
itermAdd_wf, 
itermMinus_wf, 
itermVar_wf, 
rless_functionality, 
req_weakening, 
req-iff-rsub-is-0, 
real_polynomial_null, 
istype-int, 
real_term_value_sub_lemma, 
istype-void, 
real_term_value_add_lemma, 
real_term_value_minus_lemma, 
real_term_value_var_lemma, 
real_term_value_const_lemma, 
rless_transitivity1, 
rleq_weakening_rless, 
rleq_functionality, 
rleq-iff-all-rless, 
sq_stable__rleq, 
rleq-implies-rleq, 
rleq_functionality_wrt_implies, 
rleq_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
lambdaFormation_alt, 
independent_pairFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
isectElimination, 
natural_numberEquality, 
hypothesis, 
hypothesisEquality, 
inhabitedIsType, 
sqequalRule, 
lambdaEquality_alt, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
functionIsTypeImplies, 
functionIsType, 
productIsType, 
because_Cache, 
independent_functionElimination, 
dependent_pairFormation_alt, 
approximateComputation, 
int_eqEquality, 
isect_memberEquality_alt, 
voidElimination, 
setIsType, 
setElimination, 
rename, 
imageMemberEquality, 
baseClosed, 
imageElimination
Latex:
\mforall{}[A:Set(\mBbbR{})]
    \mforall{}b,c:\mBbbR{}.    (inf(A)  =  b  {}\mRightarrow{}  (b  \mleq{}  c  \mLeftarrow{}{}\mRightarrow{}  \mforall{}e:\mBbbR{}.  ((r0  <  e)  {}\mRightarrow{}  (\mexists{}x:\mBbbR{}.  ((x  \mmember{}  A)  \mwedge{}  ((x  -  e)  \mleq{}  c))))))
Date html generated:
2019_10_29-AM-10_40_17
Last ObjectModification:
2019_04_19-PM-03_59_11
Theory : reals
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