Important/Cool HP Prime Stuff

[parisse]

Actually, the geometry document misses the ability to make a proof with the Prime, it explains only how to make conjectures. When the author takes exact coordinates, he could have emphasized that the computation for the test is done exactly, which mean that the result is a proof, but only valid for that particular choice of coordinates.
You can make a general case proof with sliders having numeric value for the display but where all computations are done symbolically.
Really sad, because that is the main difference between the geometry app on the Prime and all geometry applications on other calculators: you can make proofs with the Prime while you can only make conjectures with other calcs.