The QLP File Format

As an input for our QMIP optimization software, a new standardized file format is required. We extended the CPLEX-LP file format to handle quantifiers.

The so called QLP file format is based on the CPLEX-LP file format. Some mandantory modifications have to be considered. Exemplarily we will consider the following QMIP instance:

∃x1∈{0,1}  ∀x2∈[0,1]  ∃x3∈{0,1,2}:
min-x1-2x2-2x3
s.t. - x2- x3-1
 - x1+ x2+ x31
x1+2x2 3

A typical QLP file (belonging to the above example) looks as follows:



  1. The keywords are
    MAXIMIZE / MINIMIZE
    SUBJECT TO
    BOUNDS
    INFINITY
    FREE
    GENERALS
    BINARIES
    ALL*
    EXISTS*
    RANDOM*
    ORDER*
    END
    New keywords are marked with *. Every keyword has to be written in capital letters. Abbreviations are not allowed.
  2. The BOUNDS section which follows the constraint section is mandatory. Each bound definition has to begin on a new line. The general form is l≤x≤u.
  3. The BOUNDS section is followed by typifying the variables. To specify any of the variables as general integer variables, a GENERAL section has to be added; to specify any of the variables as binary integer variables, a BINARY section has to be added. In every section the variables are separated by at least one space. Moreover, every variable is marked with one of the new keywords ALL, EXISTS or RANDOM. Analogously the variables in the ALL, EXISTS and RANDOM section are separated by at least one space. In case the order of the quantification differs from the order of the variables of the objective function, the block ORDER can be used.

Potential errors:

  • Make sure that all variables are on the left-hand side of the constraint. Variables on the right-hand side are ignored.
527efb333