Nuprl Lemma : has-value-try
∀[t,n,B:Base].
  ↓((t)↓ ∧ (t?n:v.B[v] ~ t)) ∨ (∃u:Base. ((t ~ exception(n; u)) ∧ (t?n:v.B[v] ~ B[u]) ∧ (B[u])↓)) 
  supposing (t?n:v.B[v])↓
Proof
Definitions occuring in Statement : 
has-value: (a)↓
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
base: Base
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
squash: ↓T
, 
guard: {T}
, 
exists: ∃x:A. B[x]
, 
has-value: (a)↓
, 
decidable: Dec(P)
, 
all: ∀x:A. B[x]
, 
rev_implies: P 
⇐ Q
, 
not: ¬A
, 
iff: P 
⇐⇒ Q
, 
false: False
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
bnot: ¬bb
, 
bfalse: ff
, 
uiff: uiff(P;Q)
, 
btrue: tt
, 
it: ⋅
, 
unit: Unit
, 
bool: 𝔹
, 
implies: P 
⇒ Q
, 
sq_type: SQType(T)
Lemmas referenced : 
exists_wf, 
base_wf, 
has-value_wf_base, 
decidable__atom_equal_2, 
assert_of_bnot, 
iff_weakening_uiff, 
equal-wf-base, 
not_wf, 
bnot_wf, 
assert_wf, 
iff_transitivity, 
bool_subtype_base, 
bool_cases_sqequal, 
equal_wf, 
eqff_to_assert, 
assert_of_eq_atom2, 
eqtt_to_assert, 
bool_wf, 
eq_atom_wf2, 
atom2_subtype_base, 
subtype_base_sq, 
not-exception-has-value
Rules used in proof : 
cut, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
callbyvalueTry, 
hypothesis, 
inlFormation, 
independent_pairFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
sqequalRule, 
lambdaEquality, 
productEquality, 
sqequalIntensionalEquality, 
hypothesisEquality, 
baseApply, 
closedConclusion, 
baseClosed, 
imageMemberEquality, 
inrFormation, 
dependent_pairFormation, 
because_Cache, 
imageElimination, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
unionElimination, 
independent_isectElimination, 
productElimination, 
callbyvalueAtomnEq, 
atomn_eqReduceTrueSq, 
dependent_functionElimination, 
impliesFunctionality, 
voidElimination, 
promote_hyp, 
equalityElimination, 
lambdaFormation, 
independent_functionElimination, 
atomnEquality, 
cumulativity, 
instantiate, 
atomn_eqReduceFalseSq
Latex:
\mforall{}[t,n,B:Base].
    \mdownarrow{}((t)\mdownarrow{}  \mwedge{}  (t?n:v.B[v]  \msim{}  t))  \mvee{}  (\mexists{}u:Base.  ((t  \msim{}  exception(n;  u))  \mwedge{}  (t?n:v.B[v]  \msim{}  B[u])  \mwedge{}  (B[u])\mdownarrow{})) 
    supposing  (t?n:v.B[v])\mdownarrow{}
Date html generated:
2019_06_20-AM-11_21_48
Last ObjectModification:
2018_08_04-PM-02_10_07
Theory : call!by!value_1
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