Discrete mathematics

  • Equivalences / simplifications (look at MATH 161 coursebook too)
  • De Morgan’s laws
  • Conjunctive and disjunctive normal forms

Rules of inference

  • Conjuction elimination
    If A \land B is true, then both A and B are also true.
  • Conjuction introduction
    If both A and B are true, then A \land B is also true.
  • Implication elimination
    If both A and A \limplies B are true, then B is also true.
  • Implication introduction
    If both A \limplies B and B \limplies C are true, then then A \limplies C is also true.
  • Disjuction introduction
    If A is true, then both A \lor B and B \lor A are true for any B.
  • Disjuction elimination
    If A \lor B is true, then \lnot A implies B is true and \lnot B implies A is true.
  • Negation introduction
    If A \limplies (B \land (\lnot B)), then \lnot A.
  • Double negation
    \lnot(\lnot A) is equivalent to A.