Thank you all for the responds, I would say they were rich. I've read a bit of masternew.pdf, mainly things about data representation, it helped in some sense. I just remembered how I was struggling with Maxima. As far as I understood Maxima, uses some kind of lists (s- expressions?) to represent everything, but I'm not. I would really appreciate some level of abstraction above this CAS representation to make it more friendly to human.
I think the reason why expressions are so alien to me is that I'm not used to reason about math objects as expressions. For me an "expression" can be almost anything, and mathematical objects I usually deal with are elements of certain _distinct_ structures. For example log function is not an expression for me, it rather a function from one set to another (at least real numbers can act as such set). And indeed FriCAS supports me in my beliefs: (13) -> )d op log There is one exposed function called log : [1] D -> D from D if D has ELEMFUN (13) -> )sh ELEMFUN ElementaryFunctionCategory is a category constructor Abbreviation for ElementaryFunctionCategory is ELEMFUN This constructor is exposed in this frame. ────────────────────────── Operations ─────────────────────────────────── ?^? : (%,%) -> % exp : % - > % log : % -> % Basically it seems ELEMFUN to be just all types where log functions was defined. Unfortunately firefox couldn't find anything with "elem" in http://www.axiom-developer.org/axiom-website/bookvol10.2full.svg How do I figure out what types are contained in ElementaryFunctionCategory? (well, its a constructor, not a category itself, but I hope you'll understand what I need). As soon as log has indeed type of D -> D, how can I prescribe (manually) something meaningful to D? I mean something used in everyday/applied math --- algebra structures, various mappings, real numbers etc, but not expressions: (13) -> log f Function Selection for log Arguments: VARIABLE(f) [1] signature: EXPR(INT) -> EXPR(INT) implemented: slot $$ from EXPR(INT) (13) log(f) Type: Expression(Integer) -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/fricas-devel?hl=en.
