Nuprl Lemma : bag-filter-empty-iff
∀[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[b:bag(T)].  uiff(∀x:T. (x ↓∈ b 
⇒ (¬↑P[x]));↑bag-null([x∈b|P[x]]))
Proof
Definitions occuring in Statement : 
bag-member: x ↓∈ bs
, 
bag-null: bag-null(bs)
, 
bag-filter: [x∈b|p[x]]
, 
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
Definitions unfolded in proof : 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: λ2x.t[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
empty-bag: {}
, 
bag-null: bag-null(bs)
, 
null: null(as)
, 
bag-filter: [x∈b|p[x]]
, 
filter: filter(P;l)
, 
reduce: reduce(f;k;as)
, 
list_ind: list_ind, 
nil: []
, 
it: ⋅
, 
btrue: tt
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
true: True
, 
false: False
, 
not: ¬A
, 
cons-bag: x.b
, 
top: Top
, 
bool: 𝔹
, 
unit: Unit
, 
cons: [a / b]
, 
bfalse: ff
, 
sq_or: a ↓∨ b
, 
or: P ∨ Q
, 
subtype_rel: A ⊆r B
, 
squash: ↓T
, 
exists: ∃x:A. B[x]
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
sq_stable: SqStable(P)
Lemmas referenced : 
all_wf, 
bag-member_wf, 
not_wf, 
assert_wf, 
bag-null_wf, 
bag-filter_wf, 
squash_wf, 
false_wf, 
true_wf, 
bag-member-empty-iff, 
empty-bag_wf, 
uiff_wf, 
bag_filter_cons_lemma, 
bool_wf, 
eqtt_to_assert, 
list-subtype-bag, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
sq_or_wf, 
iff_weakening_uiff, 
rev_implies_wf, 
assert_witness, 
bag-member-cons, 
cons-bag_wf, 
bag_wf, 
bag_to_squash_list, 
sq_stable__uiff, 
sq_stable__all, 
sq_stable__not, 
sq_stable_from_decidable, 
decidable__assert, 
list_induction, 
list_wf, 
assert_elim, 
and_wf, 
not_assert_elim, 
btrue_neq_bfalse
Rules used in proof : 
because_Cache, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
hypothesisEquality, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
cumulativity, 
sqequalRule, 
lambdaEquality, 
functionEquality, 
hypothesis, 
applyEquality, 
functionExtensionality, 
dependent_functionElimination, 
setEquality, 
independent_pairFormation, 
isect_memberFormation, 
natural_numberEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
lambdaFormation, 
voidElimination, 
addLevel, 
productElimination, 
independent_isectElimination, 
allFunctionality, 
independent_functionElimination, 
isect_memberEquality, 
voidEquality, 
unionElimination, 
equalityElimination, 
inlFormation, 
imageMemberEquality, 
baseClosed, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
inrFormation, 
dependent_set_memberEquality, 
universeEquality, 
independent_pairEquality, 
imageElimination, 
rename, 
hyp_replacement, 
applyLambdaEquality, 
levelHypothesis, 
setElimination
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]));\muparrow{}bag-null([x\mmember{}b|P[x]]))
Date html generated:
2017_10_01-AM-08_56_15
Last ObjectModification:
2017_07_26-PM-04_38_16
Theory : bags
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