sci.op-research

Mathematica 6 can solve the problem in a couple minutes. The solution is
quite complex, having over 10 separate cases.
The Mathematica input is simply:
Minimize[{x+y,a*x+y >=4,b*x+y>=7,x>=0,y>=0},{x,y}]

wrote in message
news:1e336acc-cf9d-4753-a25e-02c9cf36088b@n36g2000hse.googlegroups.com...
> Greetings!
>
> Is there a mathematical software that solves symbolically a parametric
> linear program, like that one:
>
> min x + y
> subject to ax + y >= 4
> bx + y >= 7
> x >= 0, y >=0
>
> That is, I would like to see the solution in terms of the coefficients
> a and b:
>
> (x*, y*) = (3/(a - b), (4a - 7b)/(a - b)) if 7/a <= 4/b
> (x*, y*) = (7/a, 0), otherwise.
>
> Thanks in advance, Humberto.