Give a EBNF grammar for each of the languages below. Use the EBNF extensions wherever possible to simplify the grammars. In particular, you should eliminate explicit recursion from the grammars wherever possible. Dont forget to put single quotes around any EBNF meta symbol when using it as a token.

1. The set of all strings consisting of one or more as.

2. The set of all strings consisting of one or more as, with a comma between each a and next. (There should be no comma before the first or after the last.)

3. The set of all strings consisting of an open bracket (the symbol [) followed by a list of zero or more digits separated by commas, followed by a closing bracket (the symbol ]).