code: def solve(self, assumptions=[]):
          
  
          if self.minisat:
              if self.use_timer:
                   start_time = time.clock()
  
              # saving default SIGINT handler
              def_sigint_handler = signal.signal(signal.SIGINT, signal.SIG_DFL)
  
              self.status = pysolvers.minisatgh_solve(self.minisat, assumptions)
  
              # recovering default SIGINT handler
              def_sigint_handler = signal.signal(signal.SIGINT, def_sigint_handler)
  
              if self.use_timer:
                  self.call_time = time.clock() - start_time
                  self.accu_time += self.call_time
  
              return self.status
docs: Solve internal formula.