Nuprl Lemma : bag-combine-combine

[A,B,C:Type]. ∀[b:bag(A)]. ∀[f:A ⟶ bag(B)]. ∀[g:B ⟶ bag(C)].  (⋃x∈⋃y∈b.f[y].g[x] = ⋃x∈b.⋃y∈f[x].g[y] ∈ bag(C))


Proof




Definitions occuring in Statement :  bag-combine: x∈bs.f[x] bag: bag(T) uall: [x:A]. B[x] so_apply: x[s] function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T so_lambda: λ2x.t[x] top: Top so_apply: x[s] subtype_rel: A ⊆B uimplies: supposing a
Lemmas referenced :  bag-combine-assoc subtype_rel_bag top_wf trivial-equal bag_wf bag-combine_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut equalitySymmetry sqequalRule lemma_by_obid sqequalHypSubstitution isectElimination thin isect_memberEquality voidElimination voidEquality hypothesisEquality applyEquality hypothesis independent_isectElimination lambdaEquality because_Cache functionEquality axiomEquality

Latex:
\mforall{}[A,B,C:Type].  \mforall{}[b:bag(A)].  \mforall{}[f:A  {}\mrightarrow{}  bag(B)].  \mforall{}[g:B  {}\mrightarrow{}  bag(C)].
    (\mcup{}x\mmember{}\mcup{}y\mmember{}b.f[y].g[x]  =  \mcup{}x\mmember{}b.\mcup{}y\mmember{}f[x].g[y])



Date html generated: 2016_05_15-PM-02_29_08
Last ObjectModification: 2015_12_27-AM-09_49_51

Theory : bags


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