Nuprl Lemma : corec-value-type
∀[F:Type ⟶ Type]
  (value-type(corec(T.F[T]))) supposing ((∃n:ℕ. value-type(F^n Top)) and (∀A,B:Type.  (A ≡ B 
⇒ F[A] ≡ F[B])))
Proof
Definitions occuring in Statement : 
corec: corec(T.F[T])
, 
fun_exp: f^n
, 
nat: ℕ
, 
value-type: value-type(T)
, 
ext-eq: A ≡ B
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
value-type: value-type(T)
, 
sq_stable: SqStable(P)
, 
implies: P 
⇒ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
has-value: (a)↓
, 
exists: ∃x:A. B[x]
, 
corec: corec(T.F[T])
, 
subtype_rel: A ⊆r B
, 
nat: ℕ
, 
prop: ℙ
, 
squash: ↓T
, 
fun_exp: f^n
, 
false: False
, 
ge: i ≥ j 
, 
guard: {T}
, 
ext-eq: A ≡ B
, 
and: P ∧ Q
, 
top: Top
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
iff: P 
⇐⇒ Q
, 
not: ¬A
, 
rev_implies: P 
⇐ Q
, 
uiff: uiff(P;Q)
, 
subtract: n - m
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
true: True
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
, 
sq_type: SQType(T)
, 
bnot: ¬bb
, 
assert: ↑b
, 
compose: f o g
, 
nequal: a ≠ b ∈ T 
Lemmas referenced : 
sq_stable__has-value, 
corec_wf, 
subtype_rel_weakening, 
primrec_wf, 
top_wf, 
int_seg_wf, 
fun_exp_wf, 
value-type-has-value, 
equal_wf, 
equal-wf-base, 
base_wf, 
exists_wf, 
nat_wf, 
value-type_wf, 
all_wf, 
ext-eq_wf, 
nat_properties, 
less_than_transitivity1, 
less_than_irreflexivity, 
ge_wf, 
less_than_wf, 
primrec0_lemma, 
decidable__le, 
subtract_wf, 
false_wf, 
not-ge-2, 
less-iff-le, 
condition-implies-le, 
minus-one-mul, 
zero-add, 
minus-one-mul-top, 
minus-add, 
minus-minus, 
add-associates, 
add-swap, 
add-commutes, 
add_functionality_wrt_le, 
add-zero, 
le-add-cancel, 
eq_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_eq_int, 
le_weakening, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
neg_assert_of_eq_int, 
not-le-2, 
not-equal-2, 
le_wf, 
compose_wf, 
ext-eq_weakening, 
primrec-unroll
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
sqequalRule, 
lambdaEquality, 
applyEquality, 
functionExtensionality, 
universeEquality, 
cumulativity, 
lambdaFormation, 
productElimination, 
instantiate, 
natural_numberEquality, 
setElimination, 
rename, 
independent_isectElimination, 
dependent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
because_Cache, 
isect_memberEquality, 
axiomSqleEquality, 
functionEquality, 
intWeakElimination, 
voidElimination, 
independent_pairEquality, 
axiomEquality, 
voidEquality, 
unionElimination, 
independent_pairFormation, 
addEquality, 
intEquality, 
minusEquality, 
equalityElimination, 
dependent_pairFormation, 
promote_hyp, 
dependent_set_memberEquality
Latex:
\mforall{}[F:Type  {}\mrightarrow{}  Type]
    (value-type(corec(T.F[T])))  supposing 
          ((\mexists{}n:\mBbbN{}.  value-type(F\^{}n  Top))  and 
          (\mforall{}A,B:Type.    (A  \mequiv{}  B  {}\mRightarrow{}  F[A]  \mequiv{}  F[B])))
Date html generated:
2017_04_14-AM-07_41_47
Last ObjectModification:
2017_02_27-PM-03_13_26
Theory : co-recursion
Home
Index