input: Background: Similarly, it is not known if L (the set of all problems that can be solved in logarithmic space) is strictly contained in P or equal to P. Again, there are many complexity classes between the two, such as NL and NC, and it is not known if they are distinct or equal classes.
  Question: What lies between L and P that prevents a definitive determination of the relationship between L and P?
  Answer:<extra_id_0>.
output: <extra_id_0> complexity classes<extra_id_1>