Problem: Construct a proof for each of the following arguments, giving all necessary additional assertions. Specify the rules of
inference used at each step. (The word "or" denotes the "logical or" rather than the "exclusive or".
(a) It is not the case that IBM or Xerox will take over the copier market. If RCA returns to the computer market, then IBM will
take over the copier market. Hence, RCA will not return to the computer market.
(b)(My program runs successfully) or (the system bombs and I blow
my stack). Furthermore, (the system does not bomb) or (I don't blow my stack and my program runs successfully).
Therefore, my program runs successfully.