| Ast.Case (term, indtype, typ, patterns) ->
Ast.Case (k term, indtype, aux_opt typ, aux_patterns patterns)
| Ast.Cast (t1, t2) -> Ast.Cast (k t1, k t2)
| Ast.Case (term, indtype, typ, patterns) ->
Ast.Case (k term, indtype, aux_opt typ, aux_patterns patterns)
| Ast.Cast (t1, t2) -> Ast.Cast (k t1, k t2)