An expression is a matematical sentences containing Hexa numbers, decimal numbers labels, functions and constantes names, operateurs (+, -, * and /), parenthesis and the local (&) symbol.
The calculations are perfomed on 64bits signed integers.
The * and / operator are executed before + and - (1+2*3=7)
To include a constante name or a Function name in an expression, you must put a '=' before his name (for Example =toto+5).
To include a label name in an expression, you just put his name in the expression.
It's better not to put operators in a function or constante name. But If you realy need it, when usinf this name in an expression, put it between '"' characters (5+"=+%%").
the & symbol can be use in functions. it's the address of the current instruction. For example, LC(5) end-& will load C with the distance between the end label end the begining of the LC instruction.
When using an expression in a constante definition, you can only use numbers and constantes.
When using an expression in a function, you can use Numbers, constantes, functions, labels and & symbol.