What is the existential quantifier symbol?
3 for some
It indicates that there exists at least one element for which the statement is true.
What does negate mean in logic?
to reverse the truth value of a statement
For example, negating a true statement makes it false.
What is a tautology?
always true (i.e., PV TP)
A statement that is true in every possible interpretation.
What is the complement rule in logic?
PV TP = T
This states that the disjunction of a proposition and its negation is always true.
What does P^ -P = F signify?
a proposition and its negation cannot both be true
This is a fundamental principle in logic.
What is the identity rule in logic?
P ∧ T = P
A proposition AND true is the proposition itself.
What is the idempotent law?
P ∧ P = P
A proposition AND itself is the proposition.
What does the commutative law state?
P ∧ Q = Q ∧ P
The order of propositions does not affect the outcome.
What is the associative law?
(P ∧ Q) ∧ R = P ∧ (Q ∧ R)
The grouping of propositions does not affect the outcome.
What is the distributive law?
P ∧ (Q ∨ R) = (P ∧ Q) ∨ (P ∧ R)
This shows how conjunction distributes over disjunction.
What does double negation mean?
P = ¬(¬P)
Negating a negation returns the original proposition.
What is De Morgan’s law?
¬(P ∧ Q) = ¬P ∨ ¬Q
It describes how negation interacts with conjunction and disjunction.
What is the converse of P → Q?
Q → P
The converse switches the hypothesis and conclusion.
What is the contrapositive of P → Q?
¬Q → ¬P
The contrapositive is logically equivalent to the original statement.
What are the operations in algebra?
These symbols represent multiplication in algebraic expressions.
What is the identity property in algebra?
m + 0 = m and 0 + m = m
Adding zero to a number does not change its value.
What does negation mean in algebra?
m + (-m) = 0
A number plus its negative equals zero.
What is the commutative property in algebra?
m + n = n + m and m • n = n • m
The order of addition or multiplication does not affect the result.
What is the associative property in algebra?
(m + n) + p = m + (n + p) and m • (n • p) = (m • n) • p
The grouping of numbers does not affect the result.
What is the distributive property?
m • (n + p) = m • n + m • p
This shows how multiplication distributes over addition.
What does m • n = 0 imply?
either m = 0 or n = 0
This is a property of multiplication in algebra.
What is an order relation?
≤ (less than or equal to)
It defines how elements are compared in terms of size.
What does reflexive mean in order relations?
every integer m satisfies m ≤ m
Each element is related to itself.
What is the antisymmetric property?
if m ≤ n and n ≤ m, then m = n
This indicates that if two elements are mutually related, they are equal.