Bill Page wrote:
>
> --% SUBSET CATEGORY
>
> compSubsetCategory(["SubsetCategory",cat,R],m,e) ==
> --1. put "Subsets" property on R to allow directly coercion to subset;
> -- allow automatic coercion from subset to R but not vice versa
> e:= put(R,"Subsets",[[$lhsOfColon,"isFalse"]],e)
> --2. give the subset domain modemaps of cat plus 3 new functions
> comp(["Join",cat,C'],m,e) where
> C'() ==
> substitute($lhsOfColon,"$",C'') where
> C''() ==
> ["CATEGORY","domain",["SIGNATURE","coerce",[R,"$"]],["SIGNATURE",
> "lift",[R,"$"]],["SIGNATURE","reduce",["$",R]]]
>
> ---
>
> Is it correct to interpret this as modifying R, as a _side-effect_ of
> this declaration of S, by giving domain R some new property named
> "Subsets" with value "isFalse"? I do not understand "isFalse" and I do
> not see however how S itself is involved in this change to R.
AFAIK the exact value does not matter, just either property is
set or not.
> But
> perhaps the intent was to create a situation in which
>
> R has Subsets
>
> is be true? The property "Subsets" then being an indication to look
> for domains which inherit from the SubDomain(R,...) constructor?
>
No, "Subsets" is internat to the compiler.
> (1) -> Integer has Subsets
>
> >> System error:
> newHasTest expects category from
>
> I guess this error message contains a typo: from -> form?
>
Yes, fixed now.
--
Waldek Hebisch
[EMAIL PROTECTED]
--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---
