Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, and mechanisms, for identifying matches to a series of regular expressions, with the series of regular expressions including a first regular expression followed by a second regular expression, which avoids the potential overlap of characters used in matching the first and second regular expressions, while allowing individual deterministic finite automata (DFAs) to be used, whether standalone or as a merged DFA, which decreases the number of states required to represent the series of regular expressions. This potential overlap of characters can be avoided by adding marking states in a merged DFA as "divergent" in order to mask (e.g., ignore) a matching of the second regular expression for the potential overlap, or by using another DFA corresponding to the second regular expression for use during this divergent period.