Nuprl Lemma : colist-cases
∀[T:Type]. ∀x:colist(T). ((x ~ Ax) ∨ (x ∈ T × colist(T)))
Proof
Definitions occuring in Statement : 
colist: colist(T), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
or: P ∨ Q, 
member: t ∈ T, 
product: x:A × B[x], 
universe: Type, 
sqequal: s ~ t, 
axiom: Ax
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
ext-eq: A ≡ B, 
and: P ∧ Q, 
all: ∀x:A. B[x], 
subtype_rel: A ⊆r B, 
b-union: A ⋃ B, 
tunion: ⋃x:A.B[x], 
bool: 𝔹, 
unit: Unit, 
ifthenelse: if b then t else f fi , 
pi2: snd(t), 
bfalse: ff, 
btrue: tt, 
it: ⋅, 
or: P ∨ Q, 
top: Top
Lemmas referenced : 
colist-ext, 
colist_wf, 
pair-sq-axiom-wf, 
istype-void
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
productElimination, 
Error :lambdaFormation_alt, 
hypothesis_subsumption, 
applyEquality, 
sqequalRule, 
imageElimination, 
unionElimination, 
equalityElimination, 
Error :inlEquality_alt, 
axiomSqEquality, 
Error :equalityIsType4, 
Error :productIsType, 
Error :universeIsType, 
because_Cache, 
baseClosed, 
Error :inrEquality_alt, 
axiomEquality, 
independent_pairEquality, 
universeEquality, 
Error :isect_memberEquality_alt, 
voidElimination, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}[T:Type].  \mforall{}x:colist(T).  ((x  \msim{}  Ax)  \mvee{}  (x  \mmember{}  T  \mtimes{}  colist(T)))
Date html generated:
2019_06_20-PM-00_38_32
Last ObjectModification:
2018_10_03-PM-01_54_27
Theory : list_0
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