Given regular expressions containing only
(,),|,* and characters of an Alphabet A, how can I find the "negation" of a regular expression i.e.:
<R1> is a regular expression
<R2> = A*\<R1>
A* are all the words you can produce with A and
<Ri> the words accepted by the regular expression
Given R1, how can I find R2? Is there any algorithm to do that?