The TI-92 and similar have a full-on computer algebra system that they use when they're in exact mode [1]. It does symbolic manipulation. This is different fro

The TI-92 and similar have a full-on computer algebra system that they use when they're in exact mode [1]. It does symbolic manipulation. This is different from what the post (and linked paper) discuss, where the result will degrade to recursive real arithmetic, which is correct but only to a bounded level of precision. A CAS will always give a fully-exact (although sometimes very unwieldy) answer. [1] See page 87 here: https://sites.science.oregonstate.edu/math/home/programs/undergrad/TI_Manuals/ti92Guidebook.pdf https://sites.science.oregonstate.edu/math/home/programs/und...