Turing Machine DTime(log(n)) An Exercise from a Textbook:


  L3 := {ε,01,0011}
  
  is L3 ∈ DTime(log(n))


The answer says yes it is, it is even in DTime(1).

How is this possible? I would say it takes at least n steps to check the word. How is it possible to do it in less than n steps?
Your Turing machine just needs to read the first four symbols one the input tape that will be sufficient to to solve the problem $L3$.