a technical system of symbols used to represent special things

a statement of a mathematical relation

any notation for the representation of numbers

any notation that uses 2 characters (usually 0 and 1)

any notation that uses 10 different characters (usually the digits 0 to 9)

any mathematical notation that uses 8 different characters (usually the digits 0 to 7)

any notation that uses 12 different characters

a statement of a mathematical relation