2006 Q7

Question 7 (2006)
Correct me please!

Accept(T) = a(aa)*b
Loop(T) = (aa)*+aba
Loop(T) = a(aa)*ba(a+b)* (Correction read bellow)


Should I do this with a verbal description like assignment 4?

Q7

According to the remarks on Oct 2006 exam in Tutorial 104:

Accept: a(aa)*b
Loop: a(aa)*ba(a+b)* //To get to the loop part one a should at least be read.

I suppose one could give a verbal description, but only if there’s time...

Jasper

I was thinking, which is probably a bad thing.
That if you run 'a' you could probably exit the loop by doing a 'b', but aa* would loop for as long as there is input. I suppose then I should have had aa⁺
Second possible loop would be running an 'a', then a 'ba'. Since the input is the tape, it would not read anything further, as the head would just bounce back, and forth at those two input, but you right . It could still run an 'a' then loop a couple of times on 'aa', then go into the death trap of 'ba'. After that would it matter if we hand any further input (a+b)*?

After reading 'ba' it doesn't matter what is left on the tape, so I suppose adding the (a+b)* illustrates that it does not matter what words follow if any, your going nowhere.

Agreed with updated solution.