Re: positive definite matrix predicate

> It is consistent with the former. The domain Float does not include the
> result %i so it is an error. The other domains include the result.
Yes, but the Integer domain does not include complex unity either and in that 
case the result is automatically converted to AlgebraicNumber, which can 
represent it. Analogous behaviour in the first case could be to declare the 
result of sqrt on Float as Complex(Float).

Konstantin