Query functions have been implemented for GLPK (CPLEX breaks at the moment, I guess): These functions include:
retrieving one element of the coeff. matrix
retrieving one element of the obj function
lower bd for a variable
upper bound for a variable
lower and upper bounds for a row (these can not be handled separately at the moment)
direction of the optimization (is_max() function)
     2 Title: LEMON Reference Manual
 
     3 Author: LEMON Development Team
 
     4 Abstract: Documentation of LEMON.
 
     8 Index: /usr/share/doc/lemon/html/index.html
 
     9 Files: /usr/share/doc/lemon/html/*.html