Nuprl Lemma : closures-meet-sq'-ext
∀[P,Q:ℝ ⟶ ℙ].
  ((∃a:{a:ℝ| P a} . (∃b:ℝ [((Q b) ∧ (a < b))]))
  
⇒ (∃c:{c:ℝ| (r0 ≤ c) ∧ (c < r1)} 
       ∀a:{a:ℝ| P a} . ∀b:{b:ℝ| (Q b) ∧ (a < b)} .
         ∃a':{a':ℝ| P a'} . (∃b':{b':ℝ| (Q b') ∧ (a' < b')}  [((a ≤ a') ∧ (b' ≤ b) ∧ ((b' - a') ≤ ((b - a) * c)))]))
  
⇒ (∃y:ℝ. (y ∈ closure(λz.(↓P z)) ∧ y ∈ closure(λz.(↓Q z)))))
Proof
Definitions occuring in Statement : 
member-closure: y ∈ closure(A)
, 
rleq: x ≤ y
, 
rless: x < y
, 
rsub: x - y
, 
rmul: a * b
, 
int-to-real: r(n)
, 
real: ℝ
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
lambda: λx.A[x]
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
member: t ∈ T
, 
pi1: fst(t)
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
pi2: snd(t)
, 
subtract: n - m
, 
rabs: |x|
, 
rmax: rmax(x;y)
, 
imax: imax(a;b)
, 
ifthenelse: if b then t else f fi 
, 
le_int: i ≤z j
, 
bnot: ¬bb
, 
lt_int: i <z j
, 
btrue: tt
, 
it: ⋅
, 
bfalse: ff
, 
canonical-bound: canonical-bound(r)
, 
divide: n ÷ m
, 
absval: |i|
, 
int-to-real: r(n)
, 
let: let, 
closures-meet-sq', 
common-limit-squeeze-ext, 
sq_stable__rleq, 
converges-to_functionality, 
rmul-limit, 
constant-limit, 
req_weakening, 
rpowers-converge-ext, 
rless_functionality, 
sq_stable__rless, 
integer-bound, 
converges-implies-bounded, 
rleq_functionality_wrt_implies, 
sq-all-large-and, 
uall: ∀[x:A]. B[x]
, 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w])
, 
so_apply: x[s1;s2;s3;s4]
, 
top: Top
, 
uimplies: b supposing a
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
strict4: strict4(F)
, 
and: P ∧ Q
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
has-value: (a)↓
, 
prop: ℙ
, 
or: P ∨ Q
, 
squash: ↓T
, 
primrec: primrec(n;b;c)
, 
primtailrec: primtailrec(n;i;b;f)
, 
false: False
Lemmas referenced : 
closures-meet-sq', 
lifting-strict-spread, 
istype-void, 
strict4-apply, 
strict4-spread, 
value-type-has-value, 
int-value-type, 
has-value_wf_base, 
istype-base, 
is-exception_wf, 
istype-universe, 
strict4-divide, 
lifting-strict-callbyvalue, 
lifting-strict-decide, 
strict4-decide, 
cbv_sqequal, 
lifting-strict-less, 
exception-not-value, 
common-limit-squeeze-ext, 
sq_stable__rleq, 
converges-to_functionality, 
rmul-limit, 
constant-limit, 
req_weakening, 
rpowers-converge-ext, 
rless_functionality, 
sq_stable__rless, 
integer-bound, 
converges-implies-bounded, 
rleq_functionality_wrt_implies, 
sq-all-large-and
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
baseClosed, 
isect_memberEquality_alt, 
voidElimination, 
independent_isectElimination, 
independent_pairFormation, 
lambdaFormation_alt, 
callbyvalueAdd, 
baseApply, 
closedConclusion, 
hypothesisEquality, 
productElimination, 
intEquality, 
universeIsType, 
addExceptionCases, 
exceptionSqequal, 
inrFormation_alt, 
imageMemberEquality, 
imageElimination, 
inlFormation_alt, 
callbyvalueCallbyvalue, 
callbyvalueReduce, 
callbyvalueExceptionCases, 
because_Cache, 
callbyvalueMultiply, 
multiplyExceptionCases, 
sqleReflexivity, 
independent_functionElimination
Latex:
\mforall{}[P,Q:\mBbbR{}  {}\mrightarrow{}  \mBbbP{}].
    ((\mexists{}a:\{a:\mBbbR{}|  P  a\}  .  (\mexists{}b:\mBbbR{}  [((Q  b)  \mwedge{}  (a  <  b))]))
    {}\mRightarrow{}  (\mexists{}c:\{c:\mBbbR{}|  (r0  \mleq{}  c)  \mwedge{}  (c  <  r1)\} 
              \mforall{}a:\{a:\mBbbR{}|  P  a\}  .  \mforall{}b:\{b:\mBbbR{}|  (Q  b)  \mwedge{}  (a  <  b)\}  .
                  \mexists{}a':\{a':\mBbbR{}|  P  a'\}  .  (\mexists{}b':\{b':\mBbbR{}|  (Q  b')  \mwedge{}  (a'  <  b')\}    [((a  \mleq{}  a')  \mwedge{}  (b'  \mleq{}  b)  \mwedge{}  ((b'  -  a')  \mleq{}  ((\000Cb  -  a)  *  c)))]))
    {}\mRightarrow{}  (\mexists{}y:\mBbbR{}.  (y  \mmember{}  closure(\mlambda{}z.(\mdownarrow{}P  z))  \mwedge{}  y  \mmember{}  closure(\mlambda{}z.(\mdownarrow{}Q  z)))))
Date html generated:
2019_10_29-AM-10_42_52
Last ObjectModification:
2019_04_02-AM-11_58_51
Theory : reals
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