Hi! "If a multiplication takes one unit of time, an IF statement requires about 70 units."
Well, I would say that the opposite is true!.
Multiplications (especially of real numbers, which SAS always use) are usually expensive.
Logical comparisons are usually cheap.

BUT - everything is cheap compared to false solutions! Especially if they seem to be correct.
So, the earlier discussion by Rick about AND and SAS/IML is really great!