2 equations 2 conditions

*To*: mathgroup at smc.vnet.net*Subject*: [mg29131] 2 equations 2 conditions*From*: "Su Su Win" <susuwin at post.kek.jp>*Date*: Wed, 30 May 2001 23:28:20 -0400 (EDT)*Organization*: KEKB*Sender*: owner-wri-mathgroup at wolfram.com

Hello, I have problem. I am sorry if my question is very simple because I am only beginner and trying to familiar with for Mathematica. I have 2 equations to calculate W(i,j)=Function of (z, L(i,j)). Equation(1) is used when i>j and Equation(2) when i<=j. If I have to use if...then, how can i ask Mathematica to take the correct equation according to condition? Thanks a lot. Win