Main rules
- Units have to be used only after their declaration.
- While defining and using units, the system name is displayed in the unit index.
- The unit system cannot be defined explicitly. It is declared during its first use.
- Units can be declared in any part of the document.
- Units declared in the include files are considered declared above the first line of the current document. Therefore, they can be used beginning from the first edit line.
- When the unit system is not declared, the metric system is used by default.
- If you perform calculations in a particular unit system, you must declare all the units used in your expression.
- While using the unit declared in one system, there is no need to declare another units system if it is the same.
- Conversion of the result value to a certain system is possible if all the expression units exist in the target system.
- In unit redefinition, the rule of consequence of expressions in the document occurs: the expression uses the unit declaration located in the nearest upper position.
- Any system unit can be defined in terms of any other unit of any other system.
- Built-in units can also be redefined.
