In a problem above, you wrote an argument out in logic. Now, using propositional logic, including any of the rules that we have learned, prove that the argument is valid. Be sure to give the rule names and line numbers in your proof.

It is not the case that if electric rates go up$,$ then usage will go down, nor is it true that either new power plants will be built or bills will not be late. Therefore, usage will not go down and bills will be late. R$,$ U$,$ P$,$ B