Use EBNF notation to describe the syntax of the following language constructs.

1. A Java return statement, which could be either a return keyword followed by a semicolon, or a return keyword followed an expression then followed by a semicolon. Assume the grammar for expression has been defined as expr -> e

2. A Python return statement, either a return keyword, or return one or more expressions separated by comma.

3. Based on your syntax definition in (2), is return x+y; a valid Python return statement?