Nuprl Lemma : bar_recursion_wf0
∀[T:Type]. ∀[R,A:n:ℕ ⟶ (ℕn ⟶ T) ⟶ ℙ]. ∀[d:∀n:ℕ. ∀s:ℕn ⟶ T. Dec(R[n;s])].
∀[b:∀n:ℕ. ∀s:ℕn ⟶ T. (R[n;s]
⇒ A[n;s])]. ∀[i:∀n:ℕ. ∀s:ℕn ⟶ T. ((∀t:T. A[n + 1;seq-append(n;1;s;λi.t)])
⇒ A[n;s])].
((∀alpha:ℕ ⟶ T. (↓∃m:ℕ. R[m;alpha]))
⇒ (bar_recursion(d;b;i;0;λm.eval x = m in ⊥) ∈ A[0;λm.⊥]))
Proof
Definitions occuring in Statement :
bar_recursion: bar_recursion,
seq-append: seq-append(n;m;s1;s2)
,
int_seg: {i..j-}
,
nat: ℕ
,
bottom: ⊥
,
callbyvalue: callbyvalue,
decidable: Dec(P)
,
uall: ∀[x:A]. B[x]
,
prop: ℙ
,
so_apply: x[s1;s2]
,
all: ∀x:A. B[x]
,
exists: ∃x:A. B[x]
,
squash: ↓T
,
implies: P
⇒ Q
,
member: t ∈ T
,
lambda: λx.A[x]
,
function: x:A ⟶ B[x]
,
add: n + m
,
natural_number: $n
,
universe: Type
Definitions unfolded in proof :
label: ...$L... t
,
guard: {T}
,
lelt: i ≤ j < k
,
int_seg: {i..j-}
,
true: True
,
top: Top
,
subtract: n - m
,
squash: ↓T
,
sq_stable: SqStable(P)
,
uiff: uiff(P;Q)
,
rev_implies: P
⇐ Q
,
iff: P
⇐⇒ Q
,
or: P ∨ Q
,
decidable: Dec(P)
,
exists: ∃x:A. B[x]
,
all: ∀x:A. B[x]
,
prop: ℙ
,
not: ¬A
,
false: False
,
less_than': less_than'(a;b)
,
and: P ∧ Q
,
le: A ≤ B
,
uimplies: b supposing a
,
nat: ℕ
,
so_apply: x[s]
,
subtype_rel: A ⊆r B
,
so_apply: x[s1;s2]
,
so_lambda: λ2x.t[x]
,
implies: P
⇒ Q
,
member: t ∈ T
,
uall: ∀[x:A]. B[x]
Lemmas referenced :
ext-eq_weakening,
subtype_rel_weakening,
less_than_irreflexivity,
less_than_transitivity1,
le_reflexive,
decidable_wf,
seq-append_wf,
le_wf,
le-add-cancel,
add-zero,
add_functionality_wrt_le,
add-commutes,
add-swap,
add-associates,
minus-one-mul-top,
zero-add,
minus-one-mul,
minus-add,
condition-implies-le,
sq_stable__le,
not-le-2,
decidable__le,
false_wf,
int_seg_subtype_nat,
int_seg_wf,
subtype_rel_dep_function,
exists_wf,
squash_wf,
nat_wf,
all_wf,
bar_recursion_wf1
Rules used in proof :
equalitySymmetry,
equalityTransitivity,
instantiate,
universeEquality,
minusEquality,
intEquality,
voidEquality,
isect_memberEquality,
imageElimination,
baseClosed,
imageMemberEquality,
productElimination,
voidElimination,
unionElimination,
dependent_functionElimination,
addEquality,
dependent_set_memberEquality,
independent_pairFormation,
independent_isectElimination,
rename,
setElimination,
natural_numberEquality,
functionExtensionality,
applyEquality,
because_Cache,
lambdaEquality,
sqequalRule,
cumulativity,
functionEquality,
independent_functionElimination,
lambdaFormation,
hypothesisEquality,
thin,
isectElimination,
sqequalHypSubstitution,
hypothesis,
isect_memberFormation,
sqequalReflexivity,
computationStep,
sqequalTransitivity,
sqequalSubstitution,
extract_by_obid,
introduction,
cut
Latex:
\mforall{}[T:Type]. \mforall{}[R,A:n:\mBbbN{} {}\mrightarrow{} (\mBbbN{}n {}\mrightarrow{} T) {}\mrightarrow{} \mBbbP{}]. \mforall{}[d:\mforall{}n:\mBbbN{}. \mforall{}s:\mBbbN{}n {}\mrightarrow{} T. Dec(R[n;s])]. \mforall{}[b:\mforall{}n:\mBbbN{}. \mforall{}s:\mBbbN{}n {}\mrightarrow{} T.
(R[n;s]
{}\mRightarrow{} A[n;s])].
\mforall{}[i:\mforall{}n:\mBbbN{}. \mforall{}s:\mBbbN{}n {}\mrightarrow{} T. ((\mforall{}t:T. A[n + 1;seq-append(n;1;s;\mlambda{}i.t)]) {}\mRightarrow{} A[n;s])].
((\mforall{}alpha:\mBbbN{} {}\mrightarrow{} T. (\mdownarrow{}\mexists{}m:\mBbbN{}. R[m;alpha])) {}\mRightarrow{} (bar\_recursion(d;b;i;0;\mlambda{}m.eval x = m in \mbot{}) \mmember{} A[0;\mlambda{}m.\mbot{}]))
Date html generated:
2017_09_29-PM-05_47_35
Last ObjectModification:
2017_09_01-PM-11_45_59
Theory : bar-induction
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