Nuprl Lemma : deq-member-append
∀[A:Type]. ∀[eq:EqDecider(A)]. ∀[L1,L2:A List]. ∀[x:A].  (x ∈b L1 @ L2 ~ x ∈b L1 ∨bx ∈b L2)
Proof
Definitions occuring in Statement : 
deq-member: x ∈b L
, 
append: as @ bs
, 
list: T List
, 
deq: EqDecider(T)
, 
bor: p ∨bq
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
, 
sqequal: s ~ t
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
sq_type: SQType(T)
, 
guard: {T}
Lemmas referenced : 
subtype_base_sq, 
bool_subtype_base, 
iff_imp_equal_bool, 
deq-member_wf, 
append_wf, 
bor_wf, 
iff_transitivity, 
assert_wf, 
or_wf, 
l_member_wf, 
iff_weakening_uiff, 
assert_of_bor, 
assert-deq-member, 
member_append, 
list_wf, 
deq_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
instantiate, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
because_Cache, 
independent_isectElimination, 
hypothesis, 
hypothesisEquality, 
independent_pairFormation, 
lambdaFormation, 
independent_functionElimination, 
dependent_functionElimination, 
orFunctionality, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
sqequalAxiom, 
sqequalRule, 
isect_memberEquality, 
universeEquality
Latex:
\mforall{}[A:Type].  \mforall{}[eq:EqDecider(A)].  \mforall{}[L1,L2:A  List].  \mforall{}[x:A].    (x  \mmember{}\msubb{}  L1  @  L2  \msim{}  x  \mmember{}\msubb{}  L1  \mvee{}\msubb{}x  \mmember{}\msubb{}  L2)
Date html generated:
2016_05_14-AM-06_53_26
Last ObjectModification:
2015_12_26-PM-00_20_57
Theory : list_0
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