boolean-expressionsatboolean-algebrasatisfiabilityconjunctive-normal-form

Generating DIMACS CNF file using bc2cnf is missing AND


I tried using the bc2cnf tool to generate the DIMACS CNF file of a boolean equation.

The input file contains the equation of an AND gate as shown below :

BC1.1
f := A & B;
ASSIGN f;

Command used: ./bc2cnf -v inp.txt opt.txt

Content in the output file:

c The instance was satisfiable
c A <-> T
c B <-> T
c f <-> T
p cnf 1 1
1 0

Here, it can be observed that the correct DIMACS CNF format of the AND gate is not generated.

Please let me know how this problem can be rectified.


Solution

  • Use commandline parameter -nosimplify to suppress bc2cnf optimization.

    Result is

    c f <-> 1
    c B <-> 2
    c A <-> 3
    p cnf 3 4
    -1 2 0
    -1 3 0
    1 -3 -2 0
    1 0
    

    bc2cnf has a number of useful parameters. Try bc2cnf -? to get help.