9
Star-free Regular Languages
•Which of the following are star-free ?
•
Theorem
L is star-free iff it is in FO.
L is regular iff it is in MSO
L is star-free iff it is in FO.
L is regular iff it is in MSO
{ab, accb, ca}
S*
a*
{a,b}*
((a [ b).c)*
S*
a*
{a,b}*
((a [ b).c)*