Due to the sequential nature of the calculations done, answers of the form a*(b-c) or a/(b-c) or a/(b+c) or even a-(b*c) were not included.
The subtraction filter was such that only those of the form Ady mentioned were shown. Other all-subtraction solutions had been found by the original program.
A simpler version of the program, looking for only one operation, failed to find any solutions.
Posted by Charlie
on 2011-01-01 15:13:00