| Ast.Break -> Ast.Break
| Ast.Box (kind, terms) -> Ast.Box (kind, List.map k terms)
| Ast.Group terms -> Ast.Group (List.map k terms)
| Ast.Break -> Ast.Break
| Ast.Box (kind, terms) -> Ast.Box (kind, List.map k terms)
| Ast.Group terms -> Ast.Group (List.map k terms)