Nuprl Lemma : l_exists_wf
∀[T:Type]. ∀[L:T List]. ∀[P:{x:T| (x ∈ L)}  ⟶ ℙ].  ((∃x∈L. P[x]) ∈ ℙ)
Proof
Definitions occuring in Statement : 
l_exists: (∃x∈L. P[x])
, 
l_member: (x ∈ l)
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
member: t ∈ T
, 
set: {x:A| B[x]} 
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
l_exists: (∃x∈L. P[x])
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
prop: ℙ
, 
uimplies: b supposing a
, 
int_seg: {i..j-}
, 
sq_stable: SqStable(P)
, 
implies: P 
⇒ Q
, 
lelt: i ≤ j < k
, 
and: P ∧ Q
, 
squash: ↓T
Lemmas referenced : 
list_wf, 
sq_stable__le, 
list-subtype, 
l_member_wf, 
select_wf, 
length_wf, 
int_seg_wf, 
exists_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
cumulativity, 
hypothesisEquality, 
hypothesis, 
lambdaEquality, 
applyEquality, 
setEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
setElimination, 
rename, 
independent_functionElimination, 
productElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
axiomEquality, 
functionEquality, 
universeEquality, 
isect_memberEquality
Latex:
\mforall{}[T:Type].  \mforall{}[L:T  List].  \mforall{}[P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbP{}].    ((\mexists{}x\mmember{}L.  P[x])  \mmember{}  \mBbbP{})
Date html generated:
2016_05_14-AM-06_39_36
Last ObjectModification:
2016_01_14-PM-08_21_14
Theory : list_0
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