Nuprl Lemma : bar-induction
∀[T:Type]. ∀[R,A:(T List) ⟶ ℙ].
  ((∀s:T List. Dec(R[s]))
  
⇒ (∀s:T List. (R[s] 
⇒ A[s]))
  
⇒ (∀s:T List. ((∀t:T. A[s @ [t]]) 
⇒ A[s]))
  
⇒ (∀s:T List. ((∀alpha:ℕ ⟶ T. (↓∃n:ℕ. R[s @ map(alpha;upto(n))])) 
⇒ A[s])))
Proof
Definitions occuring in Statement : 
upto: upto(n)
, 
map: map(f;as)
, 
append: as @ bs
, 
cons: [a / b]
, 
nil: []
, 
list: T List
, 
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]
, 
squash: ↓T
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
so_apply: x[s]
, 
nat: ℕ
, 
so_apply: x[s1;s2]
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
le: A ≤ B
, 
and: P ∧ Q
, 
less_than': less_than'(a;b)
, 
false: False
, 
not: ¬A
, 
guard: {T}
, 
top: Top
, 
ge: i ≥ j 
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
squash: ↓T
, 
true: True
, 
iff: P 
⇐⇒ Q
, 
seq-adjoin: s++t
, 
seq-append: seq-append(n;m;s1;s2)
, 
less_than: a < b
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
ifthenelse: if b then t else f fi 
, 
label: ...$L... t
, 
rev_implies: P 
⇐ Q
, 
bfalse: ff
, 
sq_type: SQType(T)
, 
bnot: ¬bb
, 
assert: ↑b
, 
cand: A c∧ B
Lemmas referenced : 
bar_induction, 
list_wf, 
map_wf, 
int_seg_wf, 
upto_wf, 
nat_wf, 
all_wf, 
seq-adjoin_wf, 
squash_wf, 
exists_wf, 
append_wf, 
subtype_rel_dep_function, 
int_seg_subtype_nat, 
false_wf, 
cons_wf, 
nil_wf, 
decidable_wf, 
list_extensionality, 
length-append, 
map-length, 
length_of_cons_lemma, 
length_of_nil_lemma, 
length_upto, 
nat_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermAdd_wf, 
itermVar_wf, 
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, 
le_wf, 
select-map, 
subtype_rel_list, 
top_wf, 
less_than_wf, 
true_wf, 
length_append, 
iff_weakening_equal, 
add_functionality_wrt_eq, 
length_wf, 
map_length_nat, 
length-singleton, 
lelt_wf, 
length-map, 
intformless_wf, 
int_formula_prop_less_lemma, 
lt_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
equal_wf, 
select_upto, 
decidable__equal_int, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
decidable__lt, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
select-cons-hd, 
subtract_wf, 
itermSubtract_wf, 
int_term_value_subtract_lemma, 
select-append, 
select-upto, 
length_wf_nat, 
select_wf, 
int_seg_properties, 
seq-append_wf, 
add_nat_wf, 
add-is-int-iff, 
non_neg_length
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
sqequalRule, 
hypothesisEquality, 
lambdaEquality, 
applyEquality, 
functionExtensionality, 
cumulativity, 
hypothesis, 
natural_numberEquality, 
setElimination, 
rename, 
because_Cache, 
functionEquality, 
independent_functionElimination, 
dependent_functionElimination, 
addEquality, 
independent_isectElimination, 
independent_pairFormation, 
universeEquality, 
hyp_replacement, 
equalitySymmetry, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
dependent_set_memberEquality, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
computeAll, 
imageElimination, 
equalityTransitivity, 
productElimination, 
imageMemberEquality, 
baseClosed, 
lessCases, 
sqequalAxiom, 
equalityElimination, 
promote_hyp, 
instantiate, 
applyLambdaEquality, 
pointwiseFunctionality, 
baseApply, 
closedConclusion
Latex:
\mforall{}[T:Type].  \mforall{}[R,A:(T  List)  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}s:T  List.  Dec(R[s]))
    {}\mRightarrow{}  (\mforall{}s:T  List.  (R[s]  {}\mRightarrow{}  A[s]))
    {}\mRightarrow{}  (\mforall{}s:T  List.  ((\mforall{}t:T.  A[s  @  [t]])  {}\mRightarrow{}  A[s]))
    {}\mRightarrow{}  (\mforall{}s:T  List.  ((\mforall{}alpha:\mBbbN{}  {}\mrightarrow{}  T.  (\mdownarrow{}\mexists{}n:\mBbbN{}.  R[s  @  map(alpha;upto(n))]))  {}\mRightarrow{}  A[s])))
Date html generated:
2017_04_17-AM-08_59_46
Last ObjectModification:
2017_02_27-PM-05_16_39
Theory : list_1
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