Nuprl Lemma : bag-mapfilter-combine

∀[A,B,C:Type]. ∀[b:bag(A)]. ∀[f:A ⟶ bag(B)]. ∀[P:B ⟶ 𝔹]. ∀[g:{x:B| ↑P[x]}  ⟶ C].
  (bag-mapfilter(g;P;⋃x∈b.f[x]) = ⋃x∈b.bag-mapfilter(g;P;f[x]) ∈ bag(C))


Proof




Definitions occuring in Statement :  bag-combine: ⋃x∈bs.f[x],  bag-mapfilter: bag-mapfilter(f;P;bs),  bag: bag(T),  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,  bag-mapfilter: bag-mapfilter(f;P;bs),  so_apply: x[s],  prop: ℙ,  so_lambda: λ2x.t[x],  true: True,  squash: ↓T,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q
Lemmas referenced :  assert_wf,  bool_wf,  bag_wf,  set_wf,  bag-combine_wf,  bag-map_wf,  bag-filter_wf,  equal_wf,  squash_wf,  true_wf,  bag-filter-combine2,  iff_weakening_equal,  bag-map-combine
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  hypothesis,  functionEquality,  setEquality,  cumulativity,  hypothesisEquality,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  applyEquality,  functionExtensionality,  isect_memberEquality,  axiomEquality,  because_Cache,  universeEquality,  lambdaEquality,  natural_numberEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  baseClosed,  independent_isectElimination,  productElimination,  independent_functionElimination

Latex:
\mforall{}[A,B,C:Type].  \mforall{}[b:bag(A)].  \mforall{}[f:A  {}\mrightarrow{}  bag(B)].  \mforall{}[P:B  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[g:\{x:B|  \muparrow{}P[x]\}    {}\mrightarrow{}  C].
    (bag-mapfilter(g;P;\mcup{}x\mmember{}b.f[x])  =  \mcup{}x\mmember{}b.bag-mapfilter(g;P;f[x]))



Date html generated: 2017_10_01-AM-08_58_19
Last ObjectModification: 2017_07_26-PM-04_40_18

Theory : bags


Home Index