Now give in logical notation the literal and intended meanings of the following, choosing appropriate abbreviations for the atomic predicates:
All farmers don't have cows. The library has some books by Russell and Whitehead. All passes must be shown at the gate. Dogs must be carried on the escalator. You hit me and I'll hit you.




Show that (a) is the strongest and (d) the weakest, and that any other formula obtained by inserting \lnot \lnot (other than between "x, "y and "z) is equivalent to one of these. Restate the weakest using Ù instead.
What can be done with (ÙÁ ) and (ÚE )?
We tend to abuse Û transitively, so that f Û yÛ c means (fÛ y)Ù(yÛ c), but why is this an abuse?


