C.MutConstruct (_,_,j,_) -> reduceaux context l (List.nth pl (j-1))
| C.Appl (C.MutConstruct (_,_,j,_) :: tl) ->
let (arity, r) =
C.MutConstruct (_,_,j,_) -> reduceaux context l (List.nth pl (j-1))
| C.Appl (C.MutConstruct (_,_,j,_) :: tl) ->
let (arity, r) =