Regular Language to DFA conversion

Question

I ran into a problem in a textbook that I can't decipher and I was hoping you could help. I'm not asking for a solution, just a translation, or a push in the right direction. This is in the JFLAP textbook.

The alphabet consists only of "a".

{a^L |L = 0 (mod 6), L /= 0 (mod 4) }

Construct a DFA that recognizes this language.

I assume that if the string of a's is a multiple of 6 the string will be accepted, but I don't really understand what L/= 0 would mean. There are multiple questions like this.

Again, I don't need, or want, an answer to the problem, but maybe a translation to an english sentence would help me to understand what they are asking for.

Answer 1

L /= 0 (mod 4) means that L is not congruent to 0 mod 4 (the opposite of L = 0 (mod 4))

When you write it by hand, you actually put a slash through the symbol (like ≠)