This bug has existed since at least version 9.2   8? %macro try;%do i=1 %to %quote(2;3);%put i=&i;%end;%mend;%try; NOTE: Line generated by the invoked macro "TRY". 8 3); - 180 ERROR 180-322: Statement is not valid or it is used out of proper order. i=1 NOTE: Line generated by the invoked macro "TRY". 8 3); - 180 ERROR 180-322: Statement is not valid or it is used out of proper order. i=2 9? ... View more

You should be able to use SUBSTR() to help. Say you had a string of length 24 representing the 24 months in 2022 and 2023 and you wanted to see if someone had 3 months of enrollment that included the month of an EVENT and the next two months. data have; input id event :date. estring $24. ; format event date9.; cards; 1 01MAR2022 011111000000000000000000 2 01MAR2022 111100000000000000000000 3 01DEC2023 111111111111111111111111 ; So just calculate the index representing their event date and then take the string starting at the point and see it if starts with 3 ones to see if there is 3 months of coverage. data want; set have; index=1+intck('month','01JAN2022'd,event); if index in (1:24) then cover3 = ('111' = substrn(estring,index,3) ) ; run; The first case has 3 months coverage.  The second doesn't since it only has March and April.  The last one doesn't since we don't know about the coverage past Dec 2023. ... View more

As @Astounding pointed correctly, you'd have to use procedure (as in the description of you homework 😉). Although, the data step is incorrect anyway: You don't retain the value of OldestMother and OlderstFather to next rows when processing. So when if statements are evaluated,  you're just comparing the values within the same row, you're not considering previous values of dmage, dfage (I'd suggest to play around with this a bit and see the numbers yourself). There is no data structure provided in your question, so I'm only guessing the row consists of a couple, where in row you have age of mother and father. When you use if dfage < 99, you will exclude rows, and loose information on dmage   ... View more