Let say the following:
Bx two literals which represent
POSIX regular expressions.
Let def A as the set of literals that match
Ax. The same def for B.
Using relative complement operation, is there always regular expression for $A/B$ set, for every pair of
I attach an example:
Ax := a.* Bx := a.*b$ // The difference A/B would be Cx := a.*[^b]$