Back in the days that I used to devour everything to do with HP calculators, I remember one of the HP Notes issues which contained a summary explanation of how the Solve and Integrate algorithms worked. If I remember correctly, they were (justifiably) proud of the Integrate feature wherein the function could be undefined at the endpoints of integration.
I'm wondering now, seeing a number of emulators available, whether these algorithms have ever been published in a more detailed form? If an emulator uses a ROM, then I guess there's no coding needed. But if it is a non-ROM emulator, then what would the author do to emulate these functions?