| Ast.Fold (`Left, base_pattern, names, rec_pattern) ->
let acc_name = List.hd names in (* names can't be empty, cfr. parser *)
let meta_names =
| Ast.Fold (`Left, base_pattern, names, rec_pattern) ->
let acc_name = List.hd names in (* names can't be empty, cfr. parser *)
let meta_names =