Simulated annealing for hard satisfiability problems

A portable domestic sewing machine is provided with support means for enabling detachable accessories for use therewith during operation of the machine, such as a current regulating device and an extension table, to be firmly held in position within at least one space provided within the confines of the body of the machine, when the machine is not in use and a case or housing in which the machine with the accessories stored therein is located during non-use of the sewing machine.