I've come across this funny problem while messing around with integration by parts. Probably made a mistake somewhere. In the integration of parts expression, it's possible to expand it further. [Broken] [Broken] Plugging the second expression into the first, we get [Broken] I don't think this is standard notation, but it's better than writing out all the "violin holes". [Broken] Expanding ad infinitum we get [Broken] The problem is that it seems like we will get an infinite string of polynomials on the right hand side, but not on the left.