Nuprl Lemma : decidable__bag-member2
∀[T:Type]. ∀x:T. ((∀y:T. Dec(x = y ∈ T)) 
⇒ (∀bs:bag(T). Dec(x ↓∈ bs)))
Proof
Definitions occuring in Statement : 
bag-member: x ↓∈ bs
, 
bag: bag(T)
, 
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]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
decidable: Dec(P)
, 
member: t ∈ T
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
or: P ∨ Q
, 
guard: {T}
, 
not: ¬A
, 
uimplies: b supposing a
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
isl: isl(x)
, 
btrue: tt
, 
true: True
, 
bfalse: ff
, 
false: False
, 
squash: ↓T
, 
sq_stable: SqStable(P)
, 
exists: ∃x:A. B[x]
, 
bag-filter: [x∈b|p[x]]
, 
bag-null: bag-null(bs)
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
Lemmas referenced : 
decidable__assert, 
bag-null_wf, 
assert_wf, 
isl_wf, 
equal_wf, 
not_wf, 
bag-filter_wf, 
bag_wf, 
all_wf, 
decidable_wf, 
bag-filter-empty, 
or_wf, 
bag-member_wf, 
bag_to_squash_list, 
sq_stable__bag-member, 
list-member-bag-member, 
assert_of_null, 
equal-wf-T-base, 
list_wf, 
filter_wf5, 
l_member_wf, 
member_exists, 
member_filter, 
and_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
rename, 
cut, 
sqequalHypSubstitution, 
sqequalRule, 
introduction, 
extract_by_obid, 
dependent_functionElimination, 
thin, 
setEquality, 
cumulativity, 
hypothesisEquality, 
isectElimination, 
because_Cache, 
hypothesis, 
applyEquality, 
functionExtensionality, 
lambdaEquality, 
unionElimination, 
universeEquality, 
inrFormation, 
independent_isectElimination, 
independent_functionElimination, 
natural_numberEquality, 
voidElimination, 
equalityTransitivity, 
equalitySymmetry, 
inlFormation, 
imageElimination, 
productElimination, 
promote_hyp, 
hyp_replacement, 
applyLambdaEquality, 
setElimination, 
baseClosed, 
dependent_set_memberEquality, 
independent_pairFormation, 
imageMemberEquality
Latex:
\mforall{}[T:Type].  \mforall{}x:T.  ((\mforall{}y:T.  Dec(x  =  y))  {}\mRightarrow{}  (\mforall{}bs:bag(T).  Dec(x  \mdownarrow{}\mmember{}  bs)))
Date html generated:
2018_05_21-PM-09_46_23
Last ObjectModification:
2017_07_26-PM-06_29_59
Theory : bags_2
Home
Index