Nuprl Lemma : bag-filter-is-empty
∀[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[b:bag(T)].  uiff(∀x:T. (x ↓∈ b 
⇒ (¬↑P[x]));[x∈b|P[x]] = {} ∈ bag(T))
Proof
Definitions occuring in Statement : 
bag-member: x ↓∈ bs
, 
bag-filter: [x∈b|p[x]]
, 
empty-bag: {}
, 
bag: bag(T)
, 
assert: ↑b
, 
bool: 𝔹
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
false: False
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
bag-null: bag-null(bs)
, 
null: null(as)
, 
empty-bag: {}
, 
nil: []
, 
it: ⋅
, 
btrue: tt
, 
true: True
Lemmas referenced : 
bag-filter-empty-iff, 
all_wf, 
bag-member_wf, 
not_wf, 
assert_wf, 
equal-wf-T-base, 
bag_wf, 
bag-filter_wf, 
subtype_rel_bag, 
bool_wf, 
assert-bag-null, 
equal_functionality_wrt_subtype_rel2, 
bag-null_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
independent_pairFormation, 
productElimination, 
independent_isectElimination, 
cumulativity, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
applyEquality, 
functionExtensionality, 
dependent_functionElimination, 
voidElimination, 
setEquality, 
setElimination, 
rename, 
because_Cache, 
baseClosed, 
universeEquality, 
equalityTransitivity, 
equalitySymmetry, 
independent_functionElimination, 
natural_numberEquality, 
hyp_replacement, 
Error :applyLambdaEquality
Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[b:bag(T)].    uiff(\mforall{}x:T.  (x  \mdownarrow{}\mmember{}  b  {}\mRightarrow{}  (\mneg{}\muparrow{}P[x]));[x\mmember{}b|P[x]]  =  \{\})
Date html generated:
2016_10_25-AM-10_30_09
Last ObjectModification:
2016_07_12-AM-06_46_11
Theory : bags
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