Product automaton (source code)

= Product automaton
{title2=$Q_1\times Q_2$}

A <deterministic finite automaton> whose <automaton state> is a pair of <automaton states> of two given <deterministic finite automata>, updated componentwise by each input symbol. Choosing accepting pairs by a <Boolean function> on component acceptance realizes <intersection>, <union>, or <set difference> of the recognized <regular languages>.