Letterlike symbols are characters that resemble letters of the alphabet, but are not considered part of the standard alphabet of a language. They are used in mathematics, physics, engineering and other fields to represent specific concepts, values or physical quantities.
In mathematics, letterlike symbols are often used to represent variables, constants, or operations. For example, the symbol ∑ (sigma) is used to indicate a summation, while the symbol ∏ (pi) is used to represent the product of a set of numbers.
In physics and engineering, letterlike symbols are often used to represent physical quantities. For example, the symbol c is used to represent the speed of light, while the symbol e represents the charge on an electron.
In computing, letterlike symbols are often used to represent characters or sequences of characters that are not found in the standard keyboard. For example, the symbol ∞ is used to represent the infinity symbol.
In addition, there are many other letterlike symbols that are used in different fields and disciplines such as in logic and set theory, chemistry and many more.