Why does Derivative fail in this case?

*To*: mathgroup at smc.vnet.net*Subject*: [mg96557] Why does Derivative fail in this case?*From*: Aaron Fude <aaronfude at gmail.com>*Date*: Mon, 16 Feb 2009 06:58:26 -0500 (EST)

Hi, This example is self-explanatory: f[x_, y_] := x y g = f[##]*f[##] &; h = Derivative[1, 0][g]; g[x, y] h[x, y] I should expect that h[x, y] is 2 x y^2, but instead it is zero. How come? Version 6.0 Many thanks in advance, Aaron

**Follow-Ups**:**Re: Why does Derivative fail in this case?***From:*DrMajorBob <btreat1@austin.rr.com>