HP49/50 summation weirdness

[DavidM]

(03-18-2024 09:56 AM)J-F Garnier Wrote:  Is there a known problem with the 49G/50G summation function?

The issue you're seeing stems from the internal implementation of the Σ command, and was discussed once here in a different context.

Σ is hard-wired to pass its expression to the 50g's CAS for simplification, which in this case appears to rewrite LNP1 as LN(<expression>+1). While understandable from a symbolic viewpoint, this particular approach obviously loses the additional precision that LNP1 provides.

Sigh. This is a great example of how that forced simplification can be problematic.