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Operations on sets






The union of sets A and B is a set C that contains only elements belonging to A or B. It is denoted so:

C = . = {x│ x A or x B or both}.

It is pronounced “A union B” or “Union of A and B”.

Ex.: A = {a, b}, B = {b, c, d}, C= ; now = {a, b, c, d}.

It is convenient to illustrate operations on sets by means of Venn diagrams. Such diagrams are made of Euler circles.

Note: Euler diagrams represent relations between specific set.

B
A  
C
Ex.: A = {a, b, c, d}, B = {a, b}, C = {c}. Euler diagram is made of 3 Euler circles.

Venn diagrams reflect the standard general relations between n sets.

It is also called Venn symbol. It has domains, where n is the number of elements.

n = 2 n = 3

and so on.

Set union

Union of two sets is represented by such a diagram:

Denoted C = A B

The union itself consists of the domains that have any shading.