| (_,_,_,_,C.Inductive(isind1,lno1,tl,_)),Ref.Ref(_,Ref.Ind (isind2,i,lno2))->
if isind1 <> isind2 || lno1 <> lno2 then error ();
let _,_,arity,_ = List.nth tl i in arity
| (_,_,_,_,C.Inductive(isind1,lno1,tl,_)),Ref.Ref(_,Ref.Ind (isind2,i,lno2))->
if isind1 <> isind2 || lno1 <> lno2 then error ();
let _,_,arity,_ = List.nth tl i in arity