Turing machine

[Drastic]

Problems:

1. Consider the problem

Does the regular expression R describe a language, which contains
at least one string starting with 11 and ending with 0?

Express the problem as a language RU110 (similar in style to ATM). Prove
that RU110 is decidable.



2. Let us call a Turing machine repetitive, if it only loops forever if we encounter
the same configuration C more than once during a computation. Is ATM
undecidable for the class of repetitive Turing machines?

[fedruw]

I could get the answers within an attachment, but two things are unfocused... Why do you share other threads in the web, too, talking about it in other forums, like the USA's, or France's or Germany's? I suggest you a big audience...bye