Recode = ( sum(var1, var2, var3) > 1);
SAS will return 1/0 for true/false of comparisons. If the variables are all numeric coded 1/0 then sum is the number of 1 responses.
Caveat: the above will return 0 for the comparison if all the responses are missing. If you require that at least some number of the variables have an answer, such as 2 for example, then perhaps:
If n(var1,var2,var3)>2 then Recode = ( sum(var1, var2, var3) > 1);
Which will only assign a value to Recode when at least two of the variables have values.
If your variables have a common "root" name you can use short cut lists like sum(of var: ) The : says to use all of the variables whose names start with VAR (caution).