Justice

Plato's Republic:
What is Cephalus' definition of justice? What is Socrates' problem with Cephalus' definition? What is Polemarchus' definition of justice? How does Socrates get Polemarchus to abandon his position?  Is there something to be seeing between the lines with this? (Please don't let the last question keep you from answering if you are qualified to answer the rest). Thank you.