Jim, this is an often overlooked but important aspect of validating statistical software. When I'm problem solving, the last thing I want to worry about is whether my tool is doing computations correctly or not. I have had occasions to discuss software quality with people working on statistical computations, they would say they test their software with known data & results, but they would also test against SAS to verify correctness, so you are verifying not just SAS software but other tools as well.

A big Thank You to you and the team of unsung heroes that make it all possible.