## Farkas Lemma

Hi,
can some1 help me with the following problems using farkas' lemma ?
Use the Farkas lemma to find an alternative system to
Ax < b

and

u0, u1,....,un are elements of Rn. c ={ u0 + sum[(ui)*(li)] } where li>=0 for all i.
prove c is closed using Farkas lemma

Thanks a lot!