To write more efficient programs you can nest functions as appropriate. You can nest any functions as long as the function that is used as the argument meets the requirements for the argument. For example, you can nest the SCAN function within the SUBSTR function in an assignment statement to compute the value for MiddleInitial:

MiddleInitial=substr(scan(name,3),1,1);

This example of nested numeric functions determines the number of years between June 15, 2018, and today:

Years=intck('year','15jun2018'd,today());