using predefined expressions in functions [newbie question]

*To*: mathgroup at smc.vnet.net*Subject*: [mg100167] using predefined expressions in functions [newbie question]*From*: ChangMo <nichthierwohne at gmail.com>*Date*: Wed, 27 May 2009 04:05:31 -0400 (EDT)

Hi, I've been trying to write a function using some predefined expressions, but the function assignment seems to understand the symbols in the expressions as literals. eg., Needs["VectorAnalysis`"] R1 := {x1,y1,z1} R2 := {x2,y2,z2} f[x1_,y1_,z1_,x2_,y2_,z2_] := R1 . R2 f[1,2,3,4,5,6] gives the output x1 x2 + y1 y2 + z1 z2 instead of 32 ( = 1*4 + 2*5 + 3*6 ) Can anyone help me with this? Thanks for your attention. -ChangMo

**Follow-Ups**:**Re: using predefined expressions in functions [newbie***From:*Leonid Shifrin <lshifr@gmail.com>