Nuprl Lemma : bag-union-union-as-combine

∀[X:Type]. ∀[x:bag(bag(bag(X)))].  (bag-union(bag-union(x)) = ⋃z∈x.bag-union(z) ∈ bag(X))


Proof




Definitions occuring in Statement :  bag-combine: ⋃x∈bs.f[x],  bag-union: bag-union(bbs),  bag: bag(T),  uall: ∀[x:A]. B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  bag-combine: ⋃x∈bs.f[x],  true: True,  so_lambda: λ2x.t[x],  so_apply: x[s],  top: Top,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  squash: ↓T,  guard: {T},  iff: P ⇐⇒ Q,  and: P ∧ Q,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  prop: ℙ
Lemmas referenced :  bag_wf,  bag-union_wf,  bag-map_wf,  bag-combine_wf,  subtype_rel_bag,  top_wf,  equal_wf,  bag-combine-map,  iff_weakening_equal,  bag-union-as-combine,  squash_wf,  true_wf,  subtype_rel_self,  bag-combine-assoc
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  hypothesis,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  isect_memberEquality,  axiomEquality,  because_Cache,  universeEquality,  lambdaEquality,  natural_numberEquality,  voidElimination,  voidEquality,  applyEquality,  independent_isectElimination,  imageElimination,  imageMemberEquality,  baseClosed,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_functionElimination,  instantiate,  functionEquality

Latex:
\mforall{}[X:Type].  \mforall{}[x:bag(bag(bag(X)))].    (bag-union(bag-union(x))  =  \mcup{}z\mmember{}x.bag-union(z))



Date html generated: 2018_05_21-PM-06_24_24
Last ObjectModification: 2018_05_19-PM-05_15_18

Theory : bags


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