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Set theory

Cardinality

Number of elements in a set.

$$

\cap(A \cup B) = \cap(A) + \cap(B) - \cap(A \cap B)

\newline

\cap(A \cap B) = 0

$$

Subsets

Proper subsets

Improper subsets

Disjoint sets

$$

\cap(A \cap B) = 0

$$

Universal sets

Denoted by the synbol \(\xi\)

Power set

Product set

Set where all elements are tuples of elements from the original sets.

Example

$$

S

$$

Venn diagrams

Complement of set

All elements outside a set

Union of sets

\(\cup\) All elements in either set

Intersection of sets

\(\cap\) All elements in both sets

Relative complement

$$

A \ B = { x: x \epsilon A and x \not\epsilon B } or \ =

$$

Symmetric difference

\(A \oplus B\)

Belongs to A + belongs to B, but not both

Methods of proof of sets

Venn diagrams proofs

Set membership table

Use basic laws or proven theorems


Last update: June 11, 2023
Created: June 11, 2023