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: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
universe: Type
, 
equal: s = t ∈ T
, 
bag-member: x ↓∈ bs
, 
bag-union: bag-union(bbs)
, 
empty-bag: {}
, 
bag: bag(T)
Lemmas : 
bag-size_wf, 
bag_wf, 
nat_wf, 
equal_wf, 
equal-wf-base-T, 
int_subtype_base, 
equal-wf-T-base, 
empty-bag-union, 
subtype_base_sq, 
bag-rep_wf, 
empty-bag_wf, 
list-subtype-bag, 
member-bag-rep, 
bag-member_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal
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:
2015_07_23-AM-11_25_32
Last ObjectModification:
2015_02_04-PM-04_46_31
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