sqrt(-1) and %i

Dear Axiom users;

I have a problem converting expressions involving sqrt(-1) to
expressions involving complex numbers and the symbol %i.

For example this works:

(2) -> p:=sin(1)*sqrt(-1)

               +---+
   (2)  sin(1)\|- 1
                                                     Type: Expression Integer

(3) -> p::Expression Complex Integer

   (3)  %i sin(1)
                                       Type: Expression Complex Integer

but not if through some more complex computation I end up with a type like this:

(4) -> q:Expression Fraction Integer:=sin(1)*sqrt(-1)

               +---+
   (4)  sin(1)\|- 1
                                        Type: Expression Fraction Integer

(5) -> q::Expression Complex Fraction Integer

   Cannot convert from type Expression Fraction Integer to Expression
      Complex Fraction Integer for value
          +---+
   sin(1)\|- 1

-------

Can anyone find a way to accomplish this coercion?

Regards,
Bill Page.