{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture #12 - Philosophy 12A Lecture#12 Expressive...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Philosophy 12A Lecture #12 2/25/10 Expressive Completeness: Recap • Set of 4 connectives (~,&,v, ) is expressively complete It is rumored that there is gold buried on the island ( G ). You ask one of the natives, a , whether there is gold on the island. He makes the following response: “There is gold on this island if and only if I am a Knight.” Is there gold buried on the island? [Answer: Yes.] a says G A A (G A) logically equivalent to G because of truth table values Inhabitant a says “Either I am a Knave or b is a Knight.” What can we infer about a and b ? [Answer: a and b are both Knights.] a says ~ A v B therefore A (~A v B) A B A (A B) = & T T T T T T F T F F F T F F T F F F F T Three of the inhabitants — a , b and c — were standing together in the garden. A stranger passed by and asked a , “Are you a Knight or...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online