A note on exploiting structure 
          when using slack variables

     A.R. Conn,  Nick Gould and Ph.L. Toint

                Report 92/18
         
We show how  to exploit  the  structure inherent in
the   linear  algebra   for  constrained  nonlinear
optimization  problems  when inequality constraints
have  been  converted  to equations by adding slack
variables  and  the  problem  is  solved  using  an
augmented Lagrangian method.