Syntax rules

An expression is composed by :

	constants
	operators
	function calls
	references
All of these components can be separated by one or more spaces. Constants
	values
	Integers are defined using figures and the '-' character for negative values : 5, -4, 3547, -1000. floats are defined using figures, the '-' character for negative values, and the '.' character : -45.248, 0.0001, 65425.124 texts are enclosed by two " characters : "this is a text". The character " can be omitted if there is no risk to interpret the text as an expression. For instance "atext" can be specified without ".
	Symbolic constants
	They specified common used values, and can be used through their symbolic names. For instance, pi can be used though its symbolic name "pi" in an expression. This helps the user to input expressions more easily. Please refer to the constants documentation for a list of the constants and their corresponding values.
operators
	operators combine one or more parts of an expression to evaluate a common operation like +, /, =. An operator is specified using one or more characters. For instance, the addition is specified using the '+' character. Please refer to the operators documentation for more information.
function calls
	The functions combine one or more sub-expressions called operands, to evaluate an operation. A function is different than an operator by its syntax. A function is specified by its name, followed by its operands enclosed by parenthesis and separated by columns. For instance, rotate(x, pi/6, z) is a function call. Please refer to the functions documentation for more information.
references
	A reference is used to specify the value corresponding to a parameter, a result, or a statistic, for an entity. If the reference corresponds to a result, the value will be the evaluation of the result, which can in turn refers to another parameter, result or statistic. If the reference corresponds to a parameter, the value will be the property of the entity, corresponding to the parameter and input by the user.   When a reference corresponds to a result or a statistic, the evaluation of this reference involve the evaluation of another expression. If this expression in turn contains a reference to the first one, an infinite loop can occur, it's called a recursive expressions. Then, Celegraph alerts you and you must enter another expression.

See also
	compatibility rules