C Plus Plus 20 - Is This a Change in the APL Reduce and Scan?

Scan and reduce the scan have been with APL since almost forever. And we just need to clarify that these are six new primitives added to Jay relatively recently. They're clearly trying to address a shortcoming in generalization based on the original APL reduce and scan for those other cases. If anybody ever comes up with a case where they need it and they complain about the speed, I'll implement it and see. But until then, we're going to keep the implementation is actually in Jay.