Please see http://www.pda-solver.com for product EULA

This License allows the holder of a current valid Commercial License to the PDA 3SAT Solver to generate 500 correct solutions using the software.
It is the License holder's responsibility to keep records (using a counter in the software & appropriate recording mechanism) of the number of successful solutions the PDA 3SAT Solver software generates on their system, and to ensure that they purchase sufficient solution Licenses, in advance, for their needs.