Product of Lexical Specification
There's not enough information here to answer the question, but I can prove a pretty good guess based on how tokenizers are typically implemented.  Generally the tokenizer will run through the list of patterns, trying each one I sequence.  If one of them matches it takes the longest possible match as a token, then starts over at the top of the list.  I surmise this is the implicit background for the question.

So forinstance if you have abbbaacc and the rules a(b|c)* and b+ in that order then you'd tokenize that as abbb/a/acc.