RE: [Axiom-developer] indefinites

[Bill Page]

I wrote:

> ...
> If [x:Integer with no assigned value] was coercible to type
> Variable then it would simply be of type Polynomial Integer as
> before. But if the domains such as Polynomial and Expression
> could know that x was declared as say PostiveInteger then it
> could do things like evaluate
> 
>   0^x
> 
> as
> 
>         1
>                               Type: PositiveInteger
> 
> even though x has no assigned value.
> ...

Ah, of course what I should have written was:

> could do things like evaluate
>
>  0^x
>
> as
>
>        0
>                                Type: Expression Integer
>
> even though x has no assigned value. 
> 
> To do this, I think we need to extend the Variable domain to
> allow, for example, the following domain constructor
> 
>   Variable(PositiveInteger,x)
> 
> Then the declaration
> 
>    x:PositiveInteger
> 
> should default to
> 
>       x
>                      Type: Variable(PositiveInteger,x)
> ...