| Expr(Object) | Creates an Expr whose value is given by the supplied object. |
| Expr(ExpressionType, String) | Creates an Expr representing a Wolfram Language Integer, Real, String, or Symbol whose value is given by the supplied string (for example "2", "3.14", "Plus", or "True"). |
| Expr(Object, Object) | Creates an Expr with the given head and arguments. |