| ITEC 122 |
| 2008fall |
| ibarland |
|
|
|
home—info—lectures—exams—archive
M(x): x is a minor
R(x): x is in this room
Older(x,y): x is older than y
examples to/from English: quantifier with ^,v,->,-
Domain: all people in the class;
then try :
domain: all Hannah Montana fans.
Everybody is a minor.
Somebody is in this room.
Some minor is not in this class.
Everybody in this room is a minor. (two phrasings)
∀ z.(M(z) ∨ R(z))
∃ z.(M(z) ∧ R(z))
∀ z.(M(z) ∨ R(amy))
∃ z.(M(z) ∨ R(amy)) (watch out; tricky!)
∀ z.(R(z) → M(z))
∀ z.(¬R(z) → ¬M(z))
pushing negation over quantifiers.
How to write “Nobody is a minor”, in two ways?
Two ways for “Somebody isn't in this room?”
How about: two ways for
“Nobody is (in this room and a minor)”
“Nobody is (in this room or a minor)”
multiple quantifiers
Somebody is older than Ian.
If you're older than Ian, you're not a minor.
Nobody is older than Ian.
Everybody is younger than Ian.
Everybody is younger than Ian except Ian himself.
home—info—lectures—exams—archive
| ©2008, Ian Barland, Radford University Last modified 2008.Sep.12 (Fri) |
Please mail any suggestions (incl. typos, broken links) to iba�rland  rad�ford.edu |
 |