The PARMS statement declares the parameters of a model and optionally sets their initial values. You can also specify the
lower and upper limits of their validity range. The parameters declared by using the PARMS statement are called named parameters throughout this chapter. A model can have additional parameters: any unspecified quantity in the model specification becomes
part of the parameter vector. You can specify the following options:

LOWER=(number1 number2 …)
LOWER=(number)

specifies the lower bounds for the specified parameters. The list can contain exactly one number, which is taken to be the
lower bound for all the listed parameters in the statement, or it must contain as many values as the number of parameters
specified. A missing value, denoted by ., is a permissible value, which signifies that the parameter has no lower bound.

UPPER=(number1 number2 …)
UPPER=(number)

specifies the upper bounds for the specified parameters. The list can contain exactly one number, which is taken to be the
upper bound for all the listed parameters in the statement, or it must contain as many values as the number of parameters
specified. A missing value, denoted by ., is a permissible value, which signifies that the parameter has no upper bound.