For Friday, read chapter 2, section 6 pp' 4042 and do the problems at the end of the section'

1

• For Friday, read chapter 2, section 6 (pp. 40-42)
  and do the problems at the end of the section.
• Graded homework 3 is due at the beginning of
  class on Friday.

2
Graded Homework 2, Part II

• Dictionary
• E Internment is ended
• N IRA will negotiate
• C IRA has Catholic support
• D UDA disbands
• Whats the conclusion? The last sentence, the one
  beginning with the word So.

3

• First premise E ? N
• Second premise ( C v D) ? N
• Third premise D ? E
• Conclusion E ? (N ? C)

4

• p. 33
• 1 If the govt rigs the election there will be
  riots. However, the govt will play fair only if
  it is guaranteed victory, and it isnt
  guaranteed victory unless it rigs the election.
  So there will be riots.
• Dictionary
• G The government rigs the election.
• R There will be riots
• V The govt is guaranteed victory.

5

• First premise G ? R
• Second premise ( G ? V) ( G ? V)
• Conclusion R

6
Formal Description of the Language of Sentential
Logic (LSL)

• The lexicon
• All capital letters (augmented by any number of
  prime marks)
• the five connectives
• and
• parentheses.

7
Formation Rules

• Base clause (f-sl) Every sentence-letter of LSL
  is a well-formed formula (a wff)
• Recursion clauses
• (f-) If p is wff then the result of prefixing
  to p is a wff.
• (f-) If p and q are wffs, the result of placing
  between them and enclosing the result in
  parentheses is a wff.
• (f-v) If p and q are wffs, the result of placing
  v between them and enclosing the result in
  parentheses is a wff.
• (f-?) If p and q are wffs, the result of placing
  ? between them and enclosing the result in
  parentheses is a wff.
• (f-?) If p and q are wffs, the result of placing
  ? between them and enclosing the result in
  parentheses is a wff.
• Closure Clause Nothing is a wff in LSL if it is
  not certified by the preceding rules.