Nuprl Lemma : empty-bag-union

[T:Type]. ∀[bbs:bag(bag(T))].  ∀bs:bag(T). (bs ↓∈ bbs  (bs {} ∈ bag(T))) supposing bag-union(bbs) {} ∈ bag(T)


Proof




Definitions occuring in Statement :  uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] implies:  Q universe: Type equal: t ∈ T bag-member: x ↓∈ bs bag-union: bag-union(bbs) empty-bag: {} bag: bag(T)
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a all: x:A. B[x] implies:  Q prop: exists: x:A. B[x] subtype_rel: A ⊆B nat: sq_type: SQType(T) guard: {T} squash: T true: True iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q

Latex:
\mforall{}[T:Type].  \mforall{}[bbs:bag(bag(T))].    \mforall{}bs:bag(T).  (bs  \mdownarrow{}\mmember{}  bbs  {}\mRightarrow{}  (bs  =  \{\}))  supposing  bag-union(bbs)  =  \{\}



Date html generated: 2016_05_17-AM-11_10_04
Last ObjectModification: 2016_01_18-AM-00_11_14

Theory : process-model


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