2.2g: More SL in a FLASH

Remember to type the ">" symbol for horseshoe and the "=" symbol for the triple bar.

B: Bush is a philosopher.
H: Hobbes is a philosopher.
M: Madden is a philosopher.

  1. Bush is a philosopher unless Madden is a philosopher.
  2. Bush is a philosopher only if Madden is not.
  3. Bush is a philosopher if Madden is no philosopher.
  4. Bush is a philosopher if and only if neither Madden nor Hobbes is a philosopher.
  5. That Hobbes is a philosopher is a necessary condition for Madden to be a philsopher.

    (hint: think of "Oxygen is a necessary condition for fire": 'F>O'.)