I just found my own answer digging around in the manual.  Simplify with a side relation does the trick.

simplify(-1/3*(xjm1^2-2*xj*xjm1+xj^2+3)/(xjm1-xj),{xj-xjm1=j}) yields -1/3*(-3-h^2)/h

Ross

Texas A&M University

I just realized that the maple formatting very much didn't work for that last problem.  Without wierd formatting this time:

I have a number of expressions.  An example is:

-1/3*(xjm1^2-2*xj*xjm1+xj^2+3)/(xjm1-xj)

I would like to substitue the expression h=xj-xjm1, which in this case would result in

1/h+2*h/6.

Does anyone know how I can make this sort of substitution in Maple automatically?

Ross

Texas A&M University