Nuprl Lemma : colist-unfold_wf
∀[A,B:Type]. ∀[P:B ⟶ (Unit + (A × B))]. ∀[x:B].  (colist-unfold(P;x) ∈ colist(A))
Proof
Definitions occuring in Statement : 
colist-unfold: colist-unfold(P;x), 
colist: colist(T), 
uall: ∀[x:A]. B[x], 
unit: Unit, 
member: t ∈ T, 
function: x:A ⟶ B[x], 
product: x:A × B[x], 
union: left + right, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
colist-unfold: colist-unfold(P;x), 
colist: colist(T), 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
cons: [a / b], 
nil: [], 
isect2: T1 ⋂ T2, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
ifthenelse: if b then t else f fi , 
top: Top, 
bfalse: ff, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
subtype_rel: A ⊆r B, 
prop: ℙ
Lemmas referenced : 
unit_wf2, 
fix_wf_corec_parameter, 
b-union_wf, 
top_wf, 
it_wf, 
subtype_rel_b-union-left, 
subtype_rel_b-union-right, 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
sqequalHypSubstitution, 
hypothesis, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
hypothesisEquality, 
isect_memberEquality, 
isectElimination, 
thin, 
because_Cache, 
functionEquality, 
cumulativity, 
unionEquality, 
extract_by_obid, 
productEquality, 
universeEquality, 
lambdaEquality, 
unionElimination, 
equalityElimination, 
functionExtensionality, 
voidElimination, 
voidEquality, 
lambdaFormation, 
applyEquality, 
productElimination, 
independent_pairEquality, 
dependent_functionElimination, 
independent_functionElimination
Latex:
\mforall{}[A,B:Type].  \mforall{}[P:B  {}\mrightarrow{}  (Unit  +  (A  \mtimes{}  B))].  \mforall{}[x:B].    (colist-unfold(P;x)  \mmember{}  colist(A))
Date html generated:
2018_05_21-PM-10_20_24
Last ObjectModification:
2017_07_26-PM-06_37_26
Theory : eval!all
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