Lesson 9.3: More Sets: Union, Intersections and the Infinity Symbol
In print, the symbol for infinity is often represented by a figure that looks like the numeral eight in a horizontal position. In braille, this symbol is represented by dot six in the first cell and dots one two three four five six in the second cell.
Unions and Intersections
The intersection and union symbols are often used with set notation. In print and in braille their configurations are inverses of each other. The braille configuration for the intersection symbol is dots four six dots one four six. The braille symbol for union is dots four six dots three four six. As with any sign of operation, do not space between the intersection and union signs and any symbols which precede or follow them.
one to infinity
negative infinity to positive infinity
six plus infinity
Does the line go to infinity?
Open bracket zero comma infinity close parenthesis
open parenthesis negative infinity comma twenty close bracket
A intersect B
A union B
the union of the complement of A to B
X intersect Y equals the null set