Nuprl Lemma : strictness-decide
∀[F,G:Top].  (case ⊥ of inl(x) => F[x] | inr(x) => G[x] ~ ⊥)
Proof
Definitions occuring in Statement : 
bottom: ⊥
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
so_apply: x[s]
, 
decide: case b of inl(x) => s[x] | inr(y) => t[y]
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
has-value: (a)↓
, 
all: ∀x:A. B[x]
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
sq_type: SQType(T)
, 
implies: P 
⇒ Q
, 
guard: {T}
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
not: ¬A
, 
false: False
, 
bfalse: ff
, 
top: Top
Lemmas referenced : 
injection-eta, 
isl_wf, 
top_wf, 
bool_cases, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
eqtt_to_assert, 
bottom_diverge, 
value-type-has-value, 
union-value-type, 
eqff_to_assert, 
assert_of_bnot, 
exception-not-bottom, 
has-value_wf_base, 
is-exception_wf, 
bottom-sqle
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalSqle, 
sqleRule, 
thin, 
divergentSqle, 
callbyvalueDecide, 
sqequalHypSubstitution, 
hypothesis, 
baseClosed, 
extract_by_obid, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
because_Cache, 
unionElimination, 
instantiate, 
cumulativity, 
independent_isectElimination, 
independent_functionElimination, 
productElimination, 
sqequalRule, 
voidElimination, 
decideExceptionCases, 
axiomSqleEquality, 
unionEquality, 
baseApply, 
closedConclusion, 
hypothesisEquality, 
sqleReflexivity, 
isect_memberEquality, 
voidEquality, 
sqequalAxiom
Latex:
\mforall{}[F,G:Top].    (case  \mbot{}  of  inl(x)  =>  F[x]  |  inr(x)  =>  G[x]  \msim{}  \mbot{})
Date html generated:
2018_05_21-PM-00_02_19
Last ObjectModification:
2018_05_19-AM-07_12_51
Theory : computation
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