Variables A variable is a symbol that represents an arbitrary element of some sort . A variable can be an unqualified variable identifier or a variable identifier qualified by a sort. Usage All variables must be declared in a declare variables command.
Case is significant in variable identifiers.
Thus x and X are different variables. It can also be used to name a variable and an operator , provided the operator is not a constant of the same sort. LP uses context to disambiguate overloaded identifiers.