IsPrime(25) give 0 Ok. But: IsPrime(49) give 1 (bug ?) IsPrime(121) give 1 too IsPrime(169) give 1 too ... I suppose IsPrime(p^2) give 1 for all p prime number >= 7 Have I configurate something wrong ? I obtain this result both on my iPhone and on my Powerbook Mac. (Thank's for help. And thank's for this beautiful program. SpaceTime is very nice. And so powerful that I'm sure the departure bugs will be fixed soon)