Nuprl Lemma : second-countable-choice
∀[X:𝕌']. ∀[R:ℕ ⟶ (n:ℕ ⟶ (ℕn ⟶ ℕ) ⟶ X) ⟶ ℙ'].
  ((∀n:ℕ. ∃A:n:ℕ ⟶ (ℕn ⟶ ℕ) ⟶ X. R[n;A]) 
⇒ (∃B:n:ℕ ⟶ (ℕn ⟶ ℕ) ⟶ X. ∀n:ℕ. R[n;B_n]))
Proof
Definitions occuring in Statement : 
predicate-shift: A_x
, 
int_seg: {i..j-}
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
exists: ∃x:A. B[x]
, 
member: t ∈ T
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
nat: ℕ
, 
so_apply: x[s1;s2]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
pi1: fst(t)
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
ifthenelse: if b then t else f fi 
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
false: False
, 
not: ¬A
, 
int_seg: {i..j-}
, 
ge: i ≥ j 
, 
lelt: i ≤ j < k
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
top: Top
, 
bfalse: ff
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
assert: ↑b
, 
int_upper: {i...}
, 
decidable: Dec(P)
, 
subtract: n - m
, 
predicate-shift: A_x
, 
seq-single: seq-single(t)
, 
seq-append: seq-append(n;m;s1;s2)
, 
subtype_rel: A ⊆r B
, 
less_than: a < b
, 
true: True
, 
squash: ↓T
, 
nequal: a ≠ b ∈ T 
Lemmas referenced : 
all_wf, 
nat_wf, 
exists_wf, 
int_seg_wf, 
equal_wf, 
eq_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_eq_int, 
false_wf, 
le_wf, 
int_seg_properties, 
nat_properties, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformless_wf, 
itermVar_wf, 
itermConstant_wf, 
intformle_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_less_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_wf, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
neg_assert_of_eq_int, 
int_upper_subtype_nat, 
nequal-le-implies, 
zero-add, 
int_upper_properties, 
decidable__lt, 
intformnot_wf, 
int_formula_prop_not_lemma, 
lelt_wf, 
subtract_wf, 
decidable__le, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
add-member-int_seg2, 
intformeq_wf, 
itermAdd_wf, 
int_formula_prop_eq_lemma, 
int_term_value_add_lemma, 
add-associates, 
add-swap, 
add-commutes, 
lt_int_wf, 
assert_of_lt_int, 
less_than_wf, 
add-subtract-cancel, 
decidable__equal_int, 
predicate-shift_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
hypothesis, 
promote_hyp, 
thin, 
sqequalHypSubstitution, 
productElimination, 
instantiate, 
introduction, 
extract_by_obid, 
isectElimination, 
cumulativity, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
natural_numberEquality, 
setElimination, 
rename, 
hypothesisEquality, 
applyEquality, 
functionExtensionality, 
because_Cache, 
universeEquality, 
dependent_pairFormation, 
equalityTransitivity, 
equalitySymmetry, 
dependent_functionElimination, 
independent_functionElimination, 
unionElimination, 
equalityElimination, 
independent_isectElimination, 
dependent_set_memberEquality, 
independent_pairFormation, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
hypothesis_subsumption, 
hyp_replacement, 
addEquality, 
minusEquality, 
lessCases, 
sqequalAxiom, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
applyLambdaEquality
Latex:
\mforall{}[X:\mBbbU{}'].  \mforall{}[R:\mBbbN{}  {}\mrightarrow{}  (n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbN{})  {}\mrightarrow{}  X)  {}\mrightarrow{}  \mBbbP{}'].
    ((\mforall{}n:\mBbbN{}.  \mexists{}A:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbN{})  {}\mrightarrow{}  X.  R[n;A])  {}\mRightarrow{}  (\mexists{}B:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  \mBbbN{})  {}\mrightarrow{}  X.  \mforall{}n:\mBbbN{}.  R[n;B\_n]))
Date html generated:
2017_04_17-AM-09_36_09
Last ObjectModification:
2017_02_27-PM-05_34_25
Theory : fan-theorem
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