The variable in the RANGE statement, the ID variables, and the BY variables are available for the model program to examine, but their values should not be changed by the program.

It is shown that the integer linear programming problem with a fixed number of variables is polynomially solvable. The proof depends on methods from geometry of numbers.

In the first part of this paper, the concept of logical reduction is presented. Minimal preferred variable inequalities are introduced, and algorithms are given for their calculation. A simple ...

Missing values for variables in programming statements are treated in the same way that missing values are treated in the DATA step; that is, missing values used in expressions propagate missing ...