Nuprl Lemma : l-exists-decider_wf
∀[A:Type]. ∀[F:A ⟶ ℙ].  ∀L:A List. ∀dcd:∀k:A. Dec(F[k]).  (l-exists-decider() L dcd ∈ Dec((∃k∈L. F[k])))
Proof
Definitions occuring in Statement : 
l-exists-decider: l-exists-decider()
, 
l_exists: (∃x∈L. P[x])
, 
list: T List
, 
decidable: Dec(P)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
decidable__l_exists, 
subtype_rel: A ⊆r B
, 
implies: P 
⇒ Q
, 
so_apply: x[s]
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
Lemmas referenced : 
decidable__l_exists, 
isect_wf, 
list_wf, 
decidable_wf, 
l_exists_wf, 
l_member_wf, 
equal_wf, 
all_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaFormation, 
thin, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalHypSubstitution, 
sqequalRule, 
applyEquality, 
lambdaEquality, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
equalitySymmetry, 
functionEquality, 
cumulativity, 
universeEquality, 
setElimination, 
rename, 
setEquality, 
dependent_functionElimination, 
independent_functionElimination, 
isectEquality, 
because_Cache, 
axiomEquality, 
isect_memberEquality
Latex:
\mforall{}[A:Type].  \mforall{}[F:A  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}L:A  List.  \mforall{}dcd:\mforall{}k:A.  Dec(F[k]).    (l-exists-decider()  L  dcd  \mmember{}  Dec((\mexists{}k\mmember{}L.  F[k])))
Date html generated:
2018_05_21-PM-00_36_07
Last ObjectModification:
2018_05_19-AM-06_43_16
Theory : list_1
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