On Sat, Oct 22, 2011 at 12:06 PM, Waldek Hebisch wrote: > Bill Page wrote: >> >> On Fri, Oct 21, 2011 at 4:25 PM, Ralf Hemmecke wrote: >> > On 10/21/2011 09:17 PM, Waldek Hebisch wrote: >> >> >> >> I propose to change 'selectfirst' to 'first' and >> >> 'selectsecond' to 'second'. >> > >> >> Ok. I would prefer also that it export 'elt' so that one might write >> x.1 and x.2 or or x(1) and x(2). >> > > What type elt should have? For x(1) type is "obvious", but > for x(i) not so. >
Perhaps it is possible to overload elt as follows: elt: (%,1) -> A elt: (%,2) -> B I have seen such use of constants as domains elsewhere in FriCAS such as elt: (%,"left") -> % elt: (%,"right") -> % in aggcat.spad.pamphlet. >> Conversion from 'List Any' would also be nice >> >> [x,y]::Product(A,B) >> [x,y,z]::Product(A,Product(B,C)) >> >> where domainOf(x)=A, domainOf(y)=B etc. Conversion from 'List A' could >> be a special case >> >> [x,y]::Product(A,A) >> etc. > > Again, what type proposed convert should have? > convert: List Any -> % if A is B then convert List A -> % Of course convert can result in failure. Regards, Bill Page. -- 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.
