Nuprl Lemma : closures-meet-sq
∀[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 : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
exists: ∃x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
member: t ∈ T
, 
and: P ∧ Q
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
cand: A c∧ B
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
top: Top
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
nat: ℕ
, 
ge: i ≥ j 
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
not: ¬A
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
false: False
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
bfalse: ff
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
ifthenelse: if b then t else f fi 
, 
assert: ↑b
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
rleq: x ≤ y
, 
rnonneg: rnonneg(x)
, 
le: A ≤ B
, 
rbetween: x≤y≤z
, 
rless: x < y
, 
nat_plus: ℕ+
, 
rev_uimplies: rev_uimplies(P;Q)
, 
req_int_terms: t1 ≡ t2
, 
rge: x ≥ y
, 
real: ℝ
, 
nequal: a ≠ b ∈ T 
, 
rmul: a * b
, 
member-closure: y ∈ closure(A)
Lemmas referenced : 
real_wf, 
rleq_wf, 
int-to-real_wf, 
rless_wf, 
subtype_rel_self, 
rsub_wf, 
rmul_wf, 
sq_stable__rleq, 
pi1_wf_top, 
istype-void, 
pi2_wf, 
primrec_wf, 
int_seg_wf, 
istype-nat, 
nat_properties, 
decidable__le, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermAdd_wf, 
itermVar_wf, 
istype-int, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_add_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
istype-le, 
primrec-unroll, 
lt_int_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
intformless_wf, 
int_formula_prop_less_lemma, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
iff_weakening_uiff, 
assert_wf, 
less_than_wf, 
istype-less_than, 
add-subtract-cancel, 
sq_stable__all, 
nat_wf, 
sq_stable__and, 
le_witness_for_triv, 
ge_wf, 
rnexp_zero_lemma, 
subtract-1-ge-0, 
radd_wf, 
rminus_wf, 
itermSubtract_wf, 
itermMinus_wf, 
nat_plus_properties, 
itermMultiply_wf, 
rleq_weakening_equal, 
rleq_functionality, 
req_weakening, 
req-iff-rsub-is-0, 
real_polynomial_null, 
real_term_value_sub_lemma, 
real_term_value_var_lemma, 
real_term_value_add_lemma, 
real_term_value_minus_lemma, 
real_term_value_const_lemma, 
real_term_value_mul_lemma, 
radd-preserves-rleq, 
subtract_wf, 
int_term_value_subtract_lemma, 
subtract-add-cancel, 
rleq-implies-rleq, 
rnexp_wf, 
rleq_functionality_wrt_implies, 
rmul_preserves_rleq2, 
ifthenelse_wf, 
eq_int_wf, 
sq_stable__less_than, 
assert_of_eq_int, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
neg_assert_of_eq_int, 
rmul_functionality, 
rnexp-req, 
rbetween_wf, 
rmul-limit, 
constant-limit, 
rpowers-converge-ext, 
rabs_wf, 
sq_stable__rless, 
rless_functionality, 
rabs-of-nonneg, 
converges-to_functionality, 
common-limit-squeeze-ext, 
member-closure_wf, 
squash_wf, 
converges-to_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
lambdaFormation_alt, 
sqequalHypSubstitution, 
productElimination, 
thin, 
setElimination, 
rename, 
cut, 
sqequalRule, 
productIsType, 
setIsType, 
universeIsType, 
introduction, 
extract_by_obid, 
hypothesis, 
isectElimination, 
natural_numberEquality, 
hypothesisEquality, 
functionIsType, 
because_Cache, 
applyEquality, 
instantiate, 
universeEquality, 
inhabitedIsType, 
dependent_pairEquality_alt, 
dependent_set_memberEquality_alt, 
dependent_functionElimination, 
dependent_pairFormation_alt, 
independent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
independent_pairFormation, 
independent_pairEquality, 
isect_memberEquality_alt, 
voidElimination, 
setEquality, 
lambdaEquality_alt, 
productEquality, 
equalityTransitivity, 
equalitySymmetry, 
promote_hyp, 
dependent_set_memberFormation_alt, 
equalityIstype, 
addEquality, 
unionElimination, 
independent_isectElimination, 
approximateComputation, 
int_eqEquality, 
functionExtensionality, 
equalityElimination, 
cumulativity, 
functionIsTypeImplies, 
intWeakElimination
Latex:
\mforall{}[P,Q:\mBbbR{}  {}\mrightarrow{}  \mBbbP{}].
    ((\mexists{}a:\{a:\mBbbR{}|  P  a\}  .  (\mexists{}b:\mBbbR{}  [((Q  b)  \mwedge{}  (a  \mleq{}  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  \mleq{}  b)\}  .
                  \mexists{}a':\{a':\mBbbR{}|  P  a'\}  .  (\mexists{}b':\{b':\mBbbR{}|  (Q  b')  \mwedge{}  (a'  \mleq{}  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_41_53
Last ObjectModification:
2019_01_08-PM-00_27_56
Theory : reals
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