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.

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 ...

Health programs that use social and related data obtained through surveys or other methods need to distinguish among so-called independent variables. Three groups of independent variables are (a) ...