Nuprl Lemma : bag-null-append
∀[T:Type]. ∀[as,bs:bag(T)].  bag-null(as + bs) = bag-null(as) ∧b bag-null(bs)
Proof
Definitions occuring in Statement : 
bag-null: bag-null(bs), 
bag-append: as + bs, 
bag: bag(T), 
band: p ∧b q, 
bool: 𝔹, 
uall: ∀[x:A]. B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
squash: ↓T, 
exists: ∃x:A. B[x], 
bag-null: bag-null(bs), 
bag-append: as + bs, 
subtype_rel: A ⊆r B, 
uimplies: b supposing a, 
top: Top, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
band: p ∧b q, 
ifthenelse: if b then t else f fi , 
uiff: uiff(P;Q), 
and: P ∧ Q, 
bfalse: ff, 
prop: ℙ
Lemmas referenced : 
bag_to_squash_list, 
null_append, 
subtype_rel_list, 
top_wf, 
null_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_null, 
equal_wf, 
bag-null_wf, 
bag-append_wf, 
list-subtype-bag, 
band_wf, 
bag_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
imageElimination, 
productElimination, 
promote_hyp, 
hypothesis, 
rename, 
sqequalRule, 
applyEquality, 
independent_isectElimination, 
lambdaEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
because_Cache, 
cumulativity, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
dependent_functionElimination, 
independent_functionElimination, 
hyp_replacement, 
applyLambdaEquality, 
axiomEquality, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}[as,bs:bag(T)].    bag-null(as  +  bs)  =  bag-null(as)  \mwedge{}\msubb{}  bag-null(bs)
Date html generated:
2017_10_01-AM-08_45_34
Last ObjectModification:
2017_07_26-PM-04_30_49
Theory : bags
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