Nuprl Lemma : decide-exception-type
∀[T:Type]. ∀[x:T]. ∀[A,B:Top].  case x of inl(u) => A[u] | inr(v) => B[v] ~ x supposing exception-type(T)
Proof
Definitions occuring in Statement : 
exception-type: exception-type(T)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
so_apply: x[s]
, 
decide: case b of inl(x) => s[x] | inr(y) => t[y]
, 
universe: Type
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
exception-type: exception-type(T)
, 
squash: ↓T
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
exception-type_wf, 
top_wf
Rules used in proof : 
universeEquality, 
equalitySymmetry, 
equalityTransitivity, 
because_Cache, 
isect_memberEquality, 
sqequalRule, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
lemma_by_obid, 
axiomSqEquality, 
hypothesis, 
pointwiseFunctionality, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
independent_isectElimination, 
closedConclusion, 
baseApply, 
baseClosed, 
imageMemberEquality, 
imageElimination, 
exceptionSqequal, 
axiomEquality, 
sqequalExtensionalEquality, 
independent_pairFormation, 
Error :lambdaFormation_alt, 
Error :universeIsType, 
sqequalIntensionalEquality
Latex:
\mforall{}[T:Type].  \mforall{}[x:T].  \mforall{}[A,B:Top].
    case  x  of  inl(u)  =>  A[u]  |  inr(v)  =>  B[v]  \msim{}  x  supposing  exception-type(T)
Date html generated:
2019_06_20-AM-11_20_53
Last ObjectModification:
2018_10_15-PM-03_25_59
Theory : call!by!value_1
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