Nuprl Lemma : bag-union-as-combine
∀[A:Type]. ∀[x:bag(bag(A))].  (bag-union(x) = ⋃b∈x.b ∈ bag(A))
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]
, 
squash: ↓T
, 
prop: ℙ
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
equal_wf, 
squash_wf, 
true_wf, 
bag_wf, 
bag-union_wf, 
bag-map-trivial, 
subtype_rel_self, 
iff_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalRule, 
applyEquality, 
thin, 
lambdaEquality, 
sqequalHypSubstitution, 
imageElimination, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
equalityTransitivity, 
hypothesis, 
equalitySymmetry, 
universeEquality, 
because_Cache, 
independent_isectElimination, 
lambdaFormation, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
instantiate, 
productElimination, 
independent_functionElimination, 
isect_memberEquality, 
axiomEquality
Latex:
\mforall{}[A:Type].  \mforall{}[x:bag(bag(A))].    (bag-union(x)  =  \mcup{}b\mmember{}x.b)
Date html generated:
2018_05_21-PM-06_24_14
Last ObjectModification:
2018_05_19-PM-05_15_11
Theory : bags
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