The symbol (element of) describes membership to a set. When reading an equation the symbol can be read as “in” or “belongs to”.

For example the above expression, , can be read as is an element of the set of real numbers, represented by the symbol .

The symbol (element of) describes membership to a set. When reading an equation the symbol can be read as “in” or “belongs to”.

For example the above expression, , can be read as is an element of the set of real numbers, represented by the symbol .