Nuprl Lemma : bag-filter-filter2
∀[T:Type]. ∀[p:T ⟶ 𝔹]. ∀[q:{x:T| ↑p[x]}  ⟶ 𝔹]. ∀[bs:bag(T)].
  ([x∈[x∈bs|p[x]]|q[x]] = [x∈bs|p[x] ∧b q[x]] ∈ bag({x:T| ↑(p[x] ∧b q[x])} ))
Proof
Definitions occuring in Statement : 
bag-filter: [x∈b|p[x]]
, 
bag: bag(T)
, 
band: p ∧b q
, 
assert: ↑b
, 
bool: 𝔹
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
set: {x:A| B[x]} 
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
squash: ↓T
, 
exists: ∃x:A. B[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
band: p ∧b q
, 
ifthenelse: if b then t else f fi 
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
bfalse: ff
, 
so_lambda: λ2x.t[x]
, 
subtype_rel: A ⊆r B
, 
rev_uimplies: rev_uimplies(P;Q)
, 
cand: A c∧ B
, 
sq_type: SQType(T)
, 
guard: {T}
, 
assert: ↑b
, 
true: True
, 
bag-filter: [x∈b|p[x]]
, 
top: Top
Lemmas referenced : 
bag_to_squash_list, 
equal_wf, 
bag_wf, 
assert_wf, 
bool_wf, 
eqtt_to_assert, 
bag-filter_wf, 
subtype_rel_bag, 
subtype_rel_sets, 
assert_of_band, 
assert_elim, 
subtype_base_sq, 
bool_subtype_base, 
set_wf, 
filter-filter, 
filter_wf4_2, 
list-subtype-bag, 
l_member_wf
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isectElimination, 
thin, 
hypothesisEquality, 
imageElimination, 
productElimination, 
promote_hyp, 
hypothesis, 
rename, 
hyp_replacement, 
equalitySymmetry, 
applyLambdaEquality, 
setEquality, 
cumulativity, 
applyEquality, 
functionExtensionality, 
because_Cache, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
sqequalRule, 
independent_isectElimination, 
dependent_set_memberEquality, 
equalityTransitivity, 
dependent_functionElimination, 
independent_functionElimination, 
lambdaEquality, 
setElimination, 
addLevel, 
levelHypothesis, 
instantiate, 
natural_numberEquality, 
independent_pairFormation, 
functionEquality, 
universeEquality, 
isect_memberFormation, 
isect_memberEquality, 
axiomEquality, 
voidElimination, 
voidEquality, 
productEquality
Latex:
\mforall{}[T:Type].  \mforall{}[p:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[q:\{x:T|  \muparrow{}p[x]\}    {}\mrightarrow{}  \mBbbB{}].  \mforall{}[bs:bag(T)].
    ([x\mmember{}[x\mmember{}bs|p[x]]|q[x]]  =  [x\mmember{}bs|p[x]  \mwedge{}\msubb{}  q[x]])
Date html generated:
2017_10_01-AM-08_45_26
Last ObjectModification:
2017_07_26-PM-04_30_42
Theory : bags
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