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: 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 ⊆B uimplies: supposing a squash: T guard: {T} iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q implies:  Q prop:
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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