Nuprl Lemma : unzip_zip
∀[T1,T2:Type]. ∀[as:T1 List]. ∀[bs:T2 List].
  unzip(zip(as;bs)) = <as, bs> ∈ (T1 List × (T2 List)) supposing ||as|| = ||bs|| ∈ ℤ
Proof
Definitions occuring in Statement : 
unzip: unzip(as)
, 
zip: zip(as;bs)
, 
length: ||as||
, 
list: T List
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
pair: <a, b>
, 
product: x:A × B[x]
, 
int: ℤ
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
nat: ℕ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
Lemmas referenced : 
unzip-zip, 
subtype_rel_list, 
top_wf, 
istype-int, 
length_wf_nat, 
set_subtype_base, 
le_wf, 
int_subtype_base, 
list_wf, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
sqequalRule, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
applyEquality, 
hypothesis, 
independent_isectElimination, 
lambdaEquality_alt, 
Error :memTop, 
universeIsType, 
independent_pairEquality, 
equalityIstype, 
intEquality, 
natural_numberEquality, 
sqequalBase, 
equalitySymmetry, 
inhabitedIsType, 
instantiate, 
universeEquality
Latex:
\mforall{}[T1,T2:Type].  \mforall{}[as:T1  List].  \mforall{}[bs:T2  List].    unzip(zip(as;bs))  =  <as,  bs>  supposing  ||as||  =  ||bs||
Date html generated:
2020_05_19-PM-09_50_38
Last ObjectModification:
2020_02_27-PM-04_07_28
Theory : list_1
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