Native Numerical Integration and Root Finder on RPN-67/97

[bshoring]

In case people haven't noticed, you can now do register arithmetic on other stack registers, like the HP-41 series, but (unlike the 41) can also do recall arithmetic. Example: STO+T, RCL/Y, etc. Also nice is the ability to save/recall the stack or even swap it with some of the secondary registers. Also Gamma and full complex number support. This is like a combined HP-67 with an HP-34C on steroids !

Very nice!