Def zip(as;bs)
Def == Case of as
Def == Canil  nil
Def == Caa.as'  Case of bs; nil  nil ; b.bs'  [<a,b> / zip(as';bs')]
Def (recursive)

is mentioned by

Thm* as:(T1T2) List. zip(1of(unzip(as));2of(unzip(as))) = as	[zip_unzip]
Thm* as:T1 List, bs:T2 List. ||as|| = ||bs||    unzip(zip(as;bs)) = <as,bs>	[unzip_zip]
Thm* as:T1 List, bs:T2 List. ||as|| = ||bs||    ||zip(as;bs)|| = ||as||	[length_zip]
Thm* as:T1 List, bs:T2 List, i:. Thm* i<||zip(as;bs)||  zip(as;bs)[i] = <as[i],bs[i]>	[select_zip]
Thm* as:T1 List, bs:T2 List. ||zip(as;bs)||||as|| & ||zip(as;bs)||||bs||	[zip_length]

Try larger context: MarkB generic IF YOU CAN SEE THIS go to /sfa/Nuprl/Shared/Xindentation_hack_doc.html