The following features are demonstrated in this example:
problem type: linear programming (generalized network flow, periodic inventory optimization)
numeric and string index sets
INIT option
NOMISS option
IMPVAR statement
reading multiple data sets
reading dense two-dimensional data
set operator DIFF
IF-THEN/ELSE expression
MOD function
CARD function
generic problem symbols _NVAR_ and _VAR_
printing sparse multi-dimensional data
.dual
variable suffix