Nuprl Lemma : decidable__exists-unit-ball-approx-1
∀k,n:ℕ.  ∀[P:unit-ball-approx(n;k) ⟶ ℙ]. ((∀p:unit-ball-approx(n;k). Dec(P[p])) ⇒ Dec(∃p:unit-ball-approx(n;k). P[p]))
Proof
Definitions occuring in Statement : 
unit-ball-approx: unit-ball-approx(n;k), 
nat: ℕ, 
decidable: Dec(P), 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
so_apply: x[s], 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
implies: P ⇒ Q, 
function: x:A ⟶ B[x]
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
uall: ∀[x:A]. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
nat: ℕ, 
le: A ≤ B, 
and: P ∧ Q, 
less_than': less_than'(a;b), 
not: ¬A, 
false: False, 
so_apply: x[s], 
prop: ℙ, 
ge: i ≥ j , 
decidable: Dec(P), 
or: P ∨ Q, 
uimplies: b supposing a, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
top: Top, 
so_lambda: λ2x.t[x], 
ext-eq: A ≡ B, 
subtype_rel: A ⊆r B, 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
less_than: a < b, 
squash: ↓T, 
unit-ball-approx: unit-ball-approx(n;k), 
subtract: n - m, 
sq_type: SQType(T), 
guard: {T}, 
cand: A c∧ B, 
sq_stable: SqStable(P), 
true: True, 
extend-approx-ball: extend-approx-ball(n;p;z), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
bnot: ¬bb, 
assert: ↑b, 
rev_implies: P ⇐ Q, 
iff: P ⇐⇒ Q
Lemmas referenced : 
unit-ball-approx_wf, 
istype-void, 
istype-le, 
decidable_wf, 
nat_properties, 
decidable__le, 
full-omega-unsat, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
intformless_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_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_wf, 
subtract_wf, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
istype-less_than, 
primrec-wf2, 
istype-nat, 
unit-ball-approx0, 
subtype_rel_self, 
int_seg_wf, 
le_wf, 
sum_wf, 
int_seg_properties, 
extend-approx-ball_wf, 
subtype_base_sq, 
int_subtype_base, 
add-associates, 
add-swap, 
add-commutes, 
zero-add, 
decidable__exists_int_seg, 
decidable__cand, 
unit-ball-approx-subtype, 
decidable__lt, 
sq_stable__le, 
sum-unroll, 
istype-top, 
lt_int_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
eqff_to_assert, 
bool_cases_sqequal, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
iff_weakening_uiff, 
assert_wf, 
less_than_wf, 
decidable__equal_int, 
intformeq_wf, 
int_formula_prop_eq_lemma
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
thin, 
isect_memberFormation_alt, 
sqequalRule, 
functionIsType, 
universeIsType, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
dependent_set_memberEquality_alt, 
natural_numberEquality, 
independent_pairFormation, 
voidElimination, 
hypothesis, 
hypothesisEquality, 
applyEquality, 
universeEquality, 
rename, 
setElimination, 
dependent_functionElimination, 
unionElimination, 
independent_isectElimination, 
approximateComputation, 
independent_functionElimination, 
dependent_pairFormation_alt, 
lambdaEquality_alt, 
int_eqEquality, 
isect_memberEquality_alt, 
isectIsType, 
because_Cache, 
productEquality, 
setIsType, 
instantiate, 
isectEquality, 
functionEquality, 
cumulativity, 
inhabitedIsType, 
productElimination, 
inlFormation_alt, 
productIsType, 
inrFormation_alt, 
hyp_replacement, 
equalitySymmetry, 
applyLambdaEquality, 
minusEquality, 
addEquality, 
imageElimination, 
multiplyEquality, 
equalityTransitivity, 
intEquality, 
imageMemberEquality, 
baseClosed, 
lessCases, 
axiomSqEquality, 
isectIsTypeImplies, 
functionExtensionality, 
equalityElimination, 
equalityIstype, 
promote_hyp
Latex:
\mforall{}k,n:\mBbbN{}.
    \mforall{}[P:unit-ball-approx(n;k)  {}\mrightarrow{}  \mBbbP{}]
        ((\mforall{}p:unit-ball-approx(n;k).  Dec(P[p]))  {}\mRightarrow{}  Dec(\mexists{}p:unit-ball-approx(n;k).  P[p]))
Date html generated:
2019_10_30-AM-11_28_22
Last ObjectModification:
2019_07_30-AM-11_30_01
Theory : real!vectors
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