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Formulæ

Formulæ consist of operators with operands. Operators are predeclared pieces of program which compute a value determined by their operands. Algol 68 is provided with a rich set of operators in the standard prelude and you can define as many more as you want. In this chapter, we shall examine all the operators in the standard prelude which can take operands of mode `INT`, `REAL` or `CHAR`. In chapter 6, we shall return to operators and look at what they do in more detail, as well as how to define new ones.

Operators are written as a combination of one or more symbols, or in capital letters like a mode indicant. We shall meet both kinds in this chapter.

HR> Subsections

- Monadic operators
- Dyadic operators
  - Exercises
- Multiplication
  - Exercises
- Division
  - Exercises
- Exponentiation
  - Exercises
- Mixed arithmetic
- Order of elaboration
- Changing the mode
  - Exercises
- Miscellaneous operators
- Operators using `CHAR`
- `print` revisited
- Summary
  - Exercises