TTT, Chapter 6, pages 141-163.
This is a hard read, since it's very technical and the concepts are
not discussed in great detail. Read it once or twice, and
try to get the most out of it!
If you have questions about something explained in the text, write it
up, bring it to class, and ask it at the beginning of
Soundness and completeness. (6 points)
- Read carefully TTT, page 153-4 again.
- In yesterday's class we've seen a semantic way of testing the
validity of an argument (truth tables) and a syntactic way
(Natural deduction rules). An important question to ask is
"How can we know that both ways
- Write a paragraph or two in which you explain as detailed as
possible what soundness and completeness
is. (Imagine that you explain these concepts to your
friend who has never heard about logic before!)
Natural Deduction. (4 points)
- Give a proof using the rules of Natural Deduction (Handout) that
from (A & B) v (A & not-B) you can derive A.
- Show that the argument is valid using the semantic method.