Nuprl Lemma : bag-member-mapfilter
∀[T,U:Type]. ∀[P:T ⟶ 𝔹]. ∀[x:U]. ∀[bs:bag(T)]. ∀[f:{x:T| ↑(P x)}  ⟶ U].
  uiff(x ↓∈ bag-mapfilter(f;P;bs);↓∃v:{x:T| ↑(P x)} . (v ↓∈ bs ∧ (x = (f v) ∈ U)))
Proof
Definitions occuring in Statement : 
bag-member: x ↓∈ bs
, 
bag-mapfilter: bag-mapfilter(f;P;bs)
, 
bag: bag(T)
, 
assert: ↑b
, 
bool: 𝔹
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
and: P ∧ Q
, 
set: {x:A| B[x]} 
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
member: t ∈ T
, 
bag: bag(T)
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
and: P ∧ Q
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
uiff: uiff(P;Q)
, 
uimplies: b supposing a
, 
quotient: x,y:A//B[x; y]
, 
implies: P 
⇒ Q
, 
bag-mapfilter: bag-mapfilter(f;P;bs)
, 
bag-filter: [x∈b|p[x]]
, 
bag-map: bag-map(f;bs)
, 
mapfilter: mapfilter(f;P;L)
, 
bag-member: x ↓∈ bs
, 
squash: ↓T
, 
subtype_rel: A ⊆r B
, 
cand: A c∧ B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
uiff_wf, 
bag-member_wf, 
bag-mapfilter_wf, 
assert_wf, 
squash_wf, 
exists_wf, 
equal_wf, 
list_wf, 
list-subtype-bag, 
permutation_wf, 
equal-wf-base, 
bag_wf, 
bool_wf, 
member-permutation, 
member_wf, 
mapfilter_wf, 
member-mapfilter, 
l_member_wf, 
subtype_rel_dep_function, 
subtype_rel_sets, 
assert_functionality_wrt_uiff, 
eta_conv, 
set_wf
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
sqequalHypSubstitution, 
pointwiseFunctionalityForEquality, 
cut, 
extract_by_obid, 
isectElimination, 
thin, 
cumulativity, 
hypothesisEquality, 
because_Cache, 
dependent_functionElimination, 
functionExtensionality, 
applyEquality, 
setEquality, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
lambdaFormation, 
setElimination, 
rename, 
productEquality, 
dependent_set_memberEquality, 
pertypeElimination, 
productElimination, 
equalityTransitivity, 
equalitySymmetry, 
independent_pairEquality, 
isect_memberEquality, 
imageElimination, 
independent_isectElimination, 
independent_functionElimination, 
functionEquality, 
universeEquality, 
isect_memberFormation, 
imageMemberEquality, 
baseClosed, 
dependent_pairFormation, 
independent_pairFormation
Latex:
\mforall{}[T,U:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[x:U].  \mforall{}[bs:bag(T)].  \mforall{}[f:\{x:T|  \muparrow{}(P  x)\}    {}\mrightarrow{}  U].
    uiff(x  \mdownarrow{}\mmember{}  bag-mapfilter(f;P;bs);\mdownarrow{}\mexists{}v:\{x:T|  \muparrow{}(P  x)\}  .  (v  \mdownarrow{}\mmember{}  bs  \mwedge{}  (x  =  (f  v))))
Date html generated:
2017_10_01-AM-08_54_24
Last ObjectModification:
2017_07_26-PM-04_36_04
Theory : bags
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