[GiNaC-list] unevaluated add in the result of imag_form()

Hi again, While looking into a problem in numerical evaluation in pynac, I ran into the following: ginsh - GiNaC Interactive Shell (ginac V1.5.7) <snip> Type ?? for a list of help topics.

a=(sqrt(4*(sqrt(3) - 5)*(sqrt(3) + 5) + 48) + 4*sqrt(3))/ (sqrt(3) + 5); (sqrt(48+4*(5+sqrt(3))*(-5+sqrt(3)))+4*sqrt(3))*(5+sqrt(3))^(-1) imag_part(a); (5+sqrt(3))^(-1)*sqrt(abs(48+4*(5+sqrt(3))*(-5+sqrt(3))))*sin(1/2*atan2(0,48+4*(-22)))

Note that the second argument of atan2 is an add object in a rather unusual form: 48+4*(-22) Is this intended behavior? Thanks. Burcin