1 vote

regular expression for " set of all strings over {a,b} in which there are at least two occurrences of b between any two occurrences of a ".

3 votes

0

the restriction is only on a means if there are 2 a's side by side then there should be 2 b's b/w them rt ?

but if there is no a in the language then there is no restriction on b. So question is how can we generate **only b , bb ,bbb......** out of this regular expression ?

from the given RE which is b*+b*(abb+)*ab* how can we get rid-off this a

b*+b*(abb+)***a**b*

Please tell me is this argument is right or wrong ...I'm so confused with RE

1

yes...b,bb,bb....can be generated...clear ur doubt

assume R.E ====> A+B means we can either take A or B at a time but not both...for generating any string..

and A^{*} + B*/////means we can either take A any no.of time or B any no.of time but not both...for generating any string..

and ( A + B)*///brackets are important..means we can either take A any no.of time or B any no.of time or BOTH...for generating any string..