let c_label = function
| LogicLabel (None, "Here") -> Here
| LogicLabel (None, "Pre") -> Pre
| LogicLabel (None, "Post") -> Post
| LogicLabel (None, "Exit") -> Exit
| LogicLabel (None, l) -> LabelParam l
| LogicLabel (Some stmt, _)
| StmtLabel { contents=stmt } -> At(names_at stmt.labels,stmt.sid)