Are these two context free grammar rules the same?

Question

Is there a difference between these two grammar definitions (where | denotes OR and ; is just a regular character)?

1. <foo> ::= <bar> | <foo> ; <bar>
2. <foo> ::= <bar> | <bar> ; <foo>

It seems to me that foo would match a sequence that looks like <bar> ; <bar> ; <bar> ; .... regardless of which definition is used. Am I missing something here or are they functionally the same?

Answer 1

I'd agree that they're equivalent, since the end result of both is one or more <bar>'s. But if any new rules were added to <foo> (such rules involving terminals or non-terminals other than <bar>), they probably wouldn't be equivalent anymore.