aaaaa:
        alternation - YES
        class - YES
        lookahead - NO
eeeee:
        alternation - YES
        class - YES
        lookahead - NO
iiiii:
        alternation - YES
        class - YES
        lookahead - NO
abcde:
        alternation - YES
        class - YES
        lookahead - NO
aeiou:
        alternation - YES
        class - YES
        lookahead - YES
bdfhj:
        alternation - NO
        class - NO
        lookahead - NO