A b c d e f etc. In set-builder notation the previous set looks like this. The upper and lower limits may or may not be included in the set.
Lets say that our universe contains the numbers 1 2 3 and 4 so U 1 2 3 4Let A be the set containing the numbers 1 and 2.
The same set could be described as xx is a counting number less than 10 in set-builder notation. What is included in that set. The set of all letters in the modern English alphabet. If the set contains more than one element then every two elements are separated by a comma symbol.