ConstantDeclaration = "$const" [ ConstDecl { "," ConstDecl } ] ";". ConstDecl = ExpressionName "=" ConstantExpression. ConstantExpression = { ConstantTerm | NamedExpression }. ConstantTerm = StaticSymbol | "(" ConstantExpression ")".
Constant declarations enable ground expressions to be denoted by symbolic names to be used
instead of the expressions. A symbolic name is an identifier. If a ground expression has
been given a name
A constant declaration may contain references to previous declarations of constants, boxes, tables, channels, and functions.
The declaration
The declaration