Philosophy 2340
Symbolic Logic

Fall, 2003

Advice on Chapter 14 Problems


14.3.4

> ~Ex Ey Ez Eu[(x # y & x #z & y #z & x # u & y # u & z # u) & Aw(Small(w) -> (w = x v w = y v w = z v w = u))]

This says that it is not the case that there are exactly four things that *are* small. It doesn't really say anything about how many objects there are that are *not* small.


14.3.5

> Ex (Cube(x) & Large(x) & Ay (Dodec(y) -> ~BackOf(y, x)))

Close, though. Your sentence says there is *at least* one large cube with nothing in back of it. It should say that there is *exactly* one large cube and nothing is in back of it.


Last update: September 15, 2003. 
Curtis Brown  |  Symbolic Logic   |  Philosophy Department  |   Trinity University
cbrown@trinity.edu