Nuprl Lemma : simple_more_general_fan_theorem
∀[T:ℕ ⟶ Type]
  (∀i:ℕ. Bounded(T[i]))
  
⇒ (∀[X:n:ℕ ⟶ (i:ℕn ⟶ T[i]) ⟶ ℙ]
        (∀n:ℕ. ∀s:i:ℕn ⟶ T[i].  Dec(X[n;s])) 
⇒ (∃k:ℕ [(∀f:i:ℕ ⟶ T[i]. ∃n:ℕk. X[n;f])]) 
        supposing ∀f:i:ℕ ⟶ T[i]. (↓∃n:ℕ. X[n;f])) 
  supposing ∀i:ℕ. T[i]
Proof
Definitions occuring in Statement : 
bounded-type: Bounded(T)
, 
int_seg: {i..j-}
, 
nat: ℕ
, 
decidable: Dec(P)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
sq_exists: ∃x:A [B[x]]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
natural_number: $n
, 
universe: Type
Definitions unfolded in proof : 
nequal: a ≠ b ∈ T 
, 
nat_plus: ℕ+
, 
ge: i ≥ j 
, 
seq-adjoin: s++t
, 
pi2: snd(t)
, 
project-seq: project-seq(s)
, 
pi1: fst(t)
, 
istype: istype(T)
, 
decidable: Dec(P)
, 
sq_exists: ∃x:A [B[x]]
, 
subtract: n - m
, 
gt: i > j
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
bnot: ¬bb
, 
sq_type: SQType(T)
, 
or: P ∨ Q
, 
exists: ∃x:A. B[x]
, 
bfalse: ff
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
cand: A c∧ B
, 
true: True
, 
top: Top
, 
uiff: uiff(P;Q)
, 
btrue: tt
, 
it: ⋅
, 
unit: Unit
, 
bool: 𝔹
, 
seq-append: seq-append(n;m;s1;s2)
, 
not: ¬A
, 
false: False
, 
less_than': less_than'(a;b)
, 
sq_stable: SqStable(P)
, 
guard: {T}
, 
so_apply: x[s1;s2]
, 
less_than: a < b
, 
le: A ≤ B
, 
and: P ∧ Q
, 
lelt: i ≤ j < k
, 
int_seg: {i..j-}
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
nat: ℕ
, 
prop: ℙ
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s]
, 
squash: ↓T
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
bounded-type: Bounded(T)
Lemmas referenced : 
less_than_irreflexivity, 
less_than_transitivity1, 
Error :neg_assert_of_eq_int, 
assert_of_eq_int, 
eq_int_wf, 
nat_properties, 
le-add-cancel-alt, 
mul-commutes, 
mul-associates, 
mul-distributes, 
omega-shadow, 
mul-distributes-right, 
two-mul, 
one-mul, 
minus-zero, 
le_reflexive, 
le_weakening2, 
subtype_rel_sets_simple, 
minus-minus, 
add-member-int_seg2, 
decidable__exists_int_seg, 
sq_stable_from_decidable, 
le_weakening, 
le_transitivity, 
pi2_wf, 
less_than_anti-reflexive, 
le-add-cancel2, 
not-equal-2, 
less-iff-le, 
not-lt-2, 
decidable__lt, 
Error :assert-bnot, 
decidable__int_equal, 
decidable__all_int_seg, 
subtype_rel_dep_function, 
decidable_wf, 
le-add-cancel, 
add_functionality_wrt_le, 
add-swap, 
zero-add, 
minus-add, 
condition-implies-le, 
not-le-2, 
decidable__le, 
seq-adjoin_wf, 
add-zero, 
zero-mul, 
add-mul-special, 
minus-one-mul-top, 
add-commutes, 
minus-one-mul, 
add-associates, 
not-gt-2, 
add-is-int-iff, 
subtract_nat_wf, 
subtract_wf, 
istype-assert, 
assert_of_bnot, 
iff_weakening_uiff, 
not_wf, 
bnot_wf, 
assert_wf, 
iff_transitivity, 
bool_subtype_base, 
bool_wf, 
subtype_base_sq, 
bool_cases_sqequal, 
eqff_to_assert, 
iff_weakening_equal, 
istype-less_than, 
istype-universe, 
true_wf, 
squash_wf, 
equal_wf, 
istype-void, 
istype-top, 
assert_of_lt_int, 
eqtt_to_assert, 
lt_int_wf, 
subtype_rel_self, 
subtype_rel_function, 
istype-false, 
int_seg_subtype_nat, 
seq-append_wf, 
istype-le, 
sq_stable__le, 
add_nat_wf, 
exists_wf, 
sq_exists_wf, 
all_wf, 
isect_wf, 
istype-nat, 
project-seq_wf, 
less_than_wf, 
and_wf, 
int_subtype_base, 
istype-int, 
le_wf, 
set_subtype_base, 
pi1_wf, 
equal-wf-base, 
int_seg_wf, 
nat_wf, 
basic_bar_induction
Rules used in proof : 
functionExtensionality, 
dependent_pairEquality_alt, 
functionExtensionality_alt, 
hyp_replacement, 
dependent_set_memberFormation_alt, 
inrFormation_alt, 
inlFormation_alt, 
multiplyEquality, 
setIsType, 
isectIsType, 
axiomEquality, 
sqequalBase, 
minusEquality, 
baseApply, 
cumulativity, 
promote_hyp, 
dependent_pairFormation_alt, 
universeEquality, 
instantiate, 
voidElimination, 
isectIsTypeImplies, 
isect_memberEquality_alt, 
axiomSqEquality, 
lessCases, 
equalityElimination, 
unionElimination, 
independent_pairFormation, 
equalitySymmetry, 
equalityTransitivity, 
equalityIstype, 
independent_functionElimination, 
addEquality, 
dependent_set_memberEquality_alt, 
closedConclusion, 
productIsType, 
universeIsType, 
functionIsType, 
productElimination, 
because_Cache, 
independent_isectElimination, 
intEquality, 
setElimination, 
natural_numberEquality, 
functionEquality, 
isectEquality, 
applyEquality, 
productEquality, 
isectElimination, 
extract_by_obid, 
rename, 
inhabitedIsType, 
functionIsTypeImplies, 
baseClosed, 
imageMemberEquality, 
hypothesis, 
imageElimination, 
hypothesisEquality, 
thin, 
dependent_functionElimination, 
lambdaEquality_alt, 
sqequalHypSubstitution, 
introduction, 
cut, 
lambdaFormation_alt, 
isect_memberFormation_alt, 
computationStep, 
sqequalTransitivity, 
sqequalReflexivity, 
sqequalRule, 
sqequalSubstitution
Latex:
\mforall{}[T:\mBbbN{}  {}\mrightarrow{}  Type]
    (\mforall{}i:\mBbbN{}.  Bounded(T[i]))
    {}\mRightarrow{}  (\mforall{}[X:n:\mBbbN{}  {}\mrightarrow{}  (i:\mBbbN{}n  {}\mrightarrow{}  T[i])  {}\mrightarrow{}  \mBbbP{}]
                (\mforall{}n:\mBbbN{}.  \mforall{}s:i:\mBbbN{}n  {}\mrightarrow{}  T[i].    Dec(X[n;s]))  {}\mRightarrow{}  (\mexists{}k:\mBbbN{}  [(\mforall{}f:i:\mBbbN{}  {}\mrightarrow{}  T[i].  \mexists{}n:\mBbbN{}k.  X[n;f])]) 
                supposing  \mforall{}f:i:\mBbbN{}  {}\mrightarrow{}  T[i].  (\mdownarrow{}\mexists{}n:\mBbbN{}.  X[n;f])) 
    supposing  \mforall{}i:\mBbbN{}.  T[i]
Date html generated:
2019_10_15-AM-10_20_16
Last ObjectModification:
2019_10_07-PM-04_40_21
Theory : bar-induction
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