Check equivalence of regular expressions

Couldn't parse first regexsecond regexeither regex

Equivalent

Accepted by first but not second:

Accepted by second but not first:

- a | b
- union
- a b
- concatenation
- a?
- option
- a*
- repetition (zero or more)
- a+
- repetition (at least one)
- a^N
- repetition (exact count)
- (a)
- atom
- [space]
- ignored