CIS1600 Final
odd integer
An integer is odd iff n = 2k + 1 for some integer k
divisible by
An integer n being divisible by an integer k is denoted by k | n
even integer
An integer n is even iff n = 2k for some integer k
prime integer
An integer n is prime iff n > 1 and for all positive integers r and s, if n = r, then r = 1 or s = 1. Otherwise, n is composite.
inverse
The implication ¬p ⇒ ¬q is called the inverse of p ⇒ q
contrapositive
The implication ¬q ⇒ ¬p is the contrapositive of p ⇒ q
proposition
a statement that is either true or false
negation
denoted as ¬p, is the proposition that is true when p is false and vice-versa
prime factorization theorem
every positive integer can be uniquely represented as a product of primes
converse
implication q ⇒ p is called the converse of the implication p ⇒ q
necessary condition
p is a necessary condition for q means that ¬p ⇒ ¬q, or equivalently q ⇒ p
sufficient condition
p is a sufficient condition for q means p ⇒ q
biconditional
p ⇐⇒ q is the proposition that is true if p and q have the same truth values and is false otherwise
Implication
p ⇒ q is the proposition that is false when p is true and q is false and true otherwise
conjunction
p ∧ q is the proposition that is true when both p and q are true
disjunction
p ∨ q is the proposition that is true when at least one of p or q is true
Exclusive or
p ⊕ q is the proposition that is true when exactly one of p and q is true, false otherwise