Disjunction, Conjunction and Negation

Question 1

Negation (not)

Answer 1

denial of proposition
two negations cancel each other out
the thing negated is false, then not - t is true

Question 2

conjunction (and)

Answer 2

assert the truth of two propositions
true only if both conjucts are true, otherwise it is false

Question 3

disjunction (or)

Answer 3

asserts that at least one of two propositions is true
if one or more is true, the whole thing is true

Question 4

inclusive or

Answer 4

the default in logic (unless there is information to the contrary) both disjuncts can be true at the same time

Question 5

exclusive or

Answer 5

only one of the two disjuncts can be true at the same time

Question 6

disjunctive syllogism

Answer 6

valid form
1. p or q
2. not - p
3. therefore q

Question 7

invalid version of disjunctive syllogism

Answer 7

1. if p or q
2. p
3. therefore, not - q
   (unless there is context that says otherwise)

Question 8

disjunctive proposition

Answer 8

a proposition with the form p or q, the p and q are called disjuncts