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Expression

Expressions consist of numbers, operators, functions, variables, properties and parenthesis.
Numbers:
Examples are "1", "1.0", ".1", "1.1 10^2", and "-1.1 10^-2".
Operators:
Unary operators: - and +.  Binary operators: +, -, *, /, and ^.  If parenthesis are omitted, the operations are performed in the order determined by the operator precedence and association rules.
Functions:
Of form "function [param1, param2, ...]".  The following functions are supported: Log, Log10, Exponential, SquareRoot, Sine, Cosine, Tangent, ArcSine, ArcCosine, ArcTangent, HyperbolicSine, HyperbolicCosine, HyperbolicTangent, Gamma, LogGamma, Beta, LogBeta, AbsoluteValue, Minimum, Maximum, NormalDistribution, InverseNormalDistribution, pi, and e.  Most functions require one parameter.  Exceptions are Beta, LogBeta, Minimum, and Maximum which require 2 and pi and e which require zero.  Squared brackets must be used with functions.  There are also four special functions, ConstraintGreaterThanOrEqual, ConstraintGreaterThan, ConstraintLessThanOrEqual and ConstraintLessThan for specifying constraints.
Variables:
String consisting of characters, the digits 0-9 and underscores.  The first character cannot be a digit.  Examples are: "SS", "Seal_Strength", "Zone_1", and "_1".
Properties:
Of form "Symbol { Symbol }".  Examples are: "SS{Average}", "Y{Standard Deviation}" and "O2{Cpk}".  Properties are used to specify characteristics of output variable and categories of category input variables.
Rounded Parentheses:
'"(" and ")" are used to control the order that operations are performed.  Without parentheses, the operations are performed in the order determined by the operator precedence and association rules.  If in doubt about the order the operations will be performed, use parenthesis.
Multiplication operators may be omitted.  For example the expression "2 A Log[B C]" is interpreted as "2 * A * Log[B * C]".  Special types of expressions are constant expressions and differentiable expressions.
Warning:  Be sure to use rounded parenthesis for order of operation, square brackets for function calls and curved brackets for properties.  "Log[A]" means to take the log of the variable A.  "Log(A)" means to multiply the variables Log and A.  "Log{A}" is the property A of the variable Log.