Assumption -> quadratic multivariate function

*To*: mathgroup at smc.vnet.net*Subject*: [mg47225] Assumption -> quadratic multivariate function*From*: damir at 2d.com (Damir Herman)*Date*: Wed, 31 Mar 2004 02:58:15 -0500 (EST)*References*: <c40spe$mqu$1@smc.vnet.net> <c48qql$lpf$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi Peter, Thank you very much for the tip. However, instead of > f /: Dt[f, ___, {x | y, 3}, ___] = 0; I think the bulletproof assignment would be f/: Dt[f, ___, {_, k_/; k>= 3}, ___] = 0; > I suppose you would like to add > x/: Dt[x, ___, y | {y, _}, ___] = 0; > y/: Dt[y, ___, x | {x, _}, ___] = 0; > too ;-) Is this really necessay? I thought that Mathematica automatically assumes the variables are independent. Damir