George,

I'd say it's due to the fact that we are still working in p-code. And there must be more overhead involved in passing the arguments even if the function does a CPU optimal OR at it's core.

>Quite frankly, I don't know. In other instances my assumptions on what performs better have been wrong and this may be another. When VFP first introduced bitwise operators to language, I assumed that BITOR() with two values would be faster than the addition of them. My logic was that BITOR() would map directly to the processor's instruction set. In testing this, it seems that addition is faster. Why? The math co-processor? That's what I assume, but I can't offer any conclusive proof.