The MAX aggregation operator evaluates the numeric expression expression for each member of the index set index-set. The result is the maximum of the values that are returned by the expression. Missing values are handled with the SAS numeric sort order, so a missing value is treated as smaller than any non­missing value. If the index set is empty, then the result is the negative number that has the largest absolute value representable on the machine.

The following example produces the output 0.5:

proc optmodel;
   put (max{i in 2..5} 1/i);