Bill --
I have been thinking about your patch for a while. As I said in the bug audit trail, I fully agree that the bug originates from explogs2trigs. However, the more I think about it, I more I become undecided what the proper fix should be -- this is not a criticism of your patch, I really just don't know the actual fix should be. For several reasons. First, assuming the the operation makes sense, there is an immediate issue of branch cuts -- the decision has to be made and done consistently across the symbolic and numeric spectrum, otherwise this is just a disaster waiting to happen and most likely harder to debug. To get branch cuts done effectively, we would need to propagate properties about (symbolic) expressions that we currently do. Second, the expression '%i' currently has type defaulted to Complex Integer -- this is a pure hack in the interpreter because we do not have true polymorphic type in the system yet, but this is a debate I do not want to have now; that was just an observation. Now, what should be the domain of sqrt(%i)? Surely, it cannot be Complex Integer. The choice of Expression Complex Integer, in my opinion, is over-reaching -- Expression T is at the current state a sort of 'black hole' that tends to attract everything and we not know yet how to effectively handle expressions of such type. Complex AlgebraicNumber? Or Complex of an extension of Fraction Integer by sqrt(2)? In each case, why not? -- Gaby ------------------------------------------------------------------------------ Are you an open source citizen? Join us for the Open Source Bridge conference! Portland, OR, June 17-19. Two days of sessions, one day of unconference: $250. Need another reason to go? 24-hour hacker lounge. Register today! http://ad.doubleclick.net/clk;215844324;13503038;v?http://opensourcebridge.org _______________________________________________ open-axiom-devel mailing list open-axiom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open-axiom-devel
