Nuprl Lemma : bag-member-list-member
∀[T:Type]. ((∀x,y:T.  Dec(x = y ∈ T)) 
⇒ (∀L:T List. ∀b:bag(T). ∀x:T.  ((L = b ∈ bag(T)) 
⇒ x ↓∈ b 
⇒ (x ∈ L))))
Proof
Definitions occuring in Statement : 
bag-member: x ↓∈ bs
, 
bag: bag(T)
, 
l_member: (x ∈ l)
, 
list: T List
, 
decidable: Dec(P)
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
empty-bag: {}
, 
uiff: uiff(P;Q)
, 
false: False
, 
cons-bag: x.b
, 
sq_or: a ↓∨ b
, 
or: P ∨ Q
, 
rev_implies: P 
⇐ Q
, 
sq_stable: SqStable(P)
Lemmas referenced : 
bag-member_wf, 
squash_wf, 
true_wf, 
bag_wf, 
iff_weakening_equal, 
list_induction, 
list-subtype-bag, 
l_member_wf, 
list_wf, 
bag-member-empty-iff, 
nil_wf, 
bag-member-cons, 
cons_wf, 
equal_wf, 
all_wf, 
decidable_wf, 
cons_member, 
sq_stable__l_member
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
introduction, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
because_Cache, 
natural_numberEquality, 
sqequalRule, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
independent_isectElimination, 
productElimination, 
independent_functionElimination, 
functionEquality, 
cumulativity, 
voidElimination, 
voidEquality, 
rename, 
dependent_functionElimination, 
unionElimination, 
inlFormation, 
hyp_replacement, 
Error :applyLambdaEquality, 
inrFormation
Latex:
\mforall{}[T:Type].  ((\mforall{}x,y:T.    Dec(x  =  y))  {}\mRightarrow{}  (\mforall{}L:T  List.  \mforall{}b:bag(T).  \mforall{}x:T.    ((L  =  b)  {}\mRightarrow{}  x  \mdownarrow{}\mmember{}  b  {}\mRightarrow{}  (x  \mmember{}  L))))
Date html generated:
2016_10_25-AM-10_28_10
Last ObjectModification:
2016_07_12-AM-06_44_25
Theory : bags
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