FlashKeepers

Discrete Math · College

Discrete Math: Set Theory

Sets, set operations, and functions and relations from an intro discrete mathematics course.

35 cards · basic cards · AI-written, checked twice. Edit anything.

Study this set free Look inside first Get FlashKeepers for iPhone
What is a set?
A collection of distinct objects (elements), unordered.
What is an element of a set?
An object that belongs to the set. Notation 'x in A' means x is an element of set A.
Define roster notation.
Writing a set by listing all its elements in braces. Example: {1, 2, 3}.
Define set-builder notation.
Describing a set by specifying a condition its elements satisfy. Example: {x | x is an integer and x > 0}.
What is a subset?
Set A is a subset of set B if every element of A is also an element of B.
What is a proper subset?
Set A is a proper subset of B if A is a subset of B and A is not equal to B.
Define the union of two sets.
A union B is the set containing all elements in A or in B (or in both).
Define the intersection of two sets.
A intersect B is the set containing all elements that are in both A and B.
Define the complement of a set.
The complement of A contains all elements in the universal set that are not in A.
Define the difference of two sets.
A minus B is the set of all elements in A but not in B.
State De Morgan's First Law.
complement(A union B) = complement(A) intersect complement(B).
State De Morgan's Second Law.
complement(A intersect B) = complement(A) union complement(B).
State the distributive law for union over intersection.
A union (B intersect C) = (A union B) intersect (A union C).
Is the union operation commutative?
Yes. A union B = B union A for any sets A and B.
What is the cardinality of a set?
The cardinality |A| is the number of distinct elements in set A.

20 more cards in the app