-pgen(START, [name = 'p', stepper = PrimeGenStepper(2),\n\
- tester = PrimeGenTester(), event = pgen_nullev,\n\
- nsteps = 0, ntests = RabinMiller.iters(START.nbits)]) -> P")
+pgen(START, [name = 'p'[, [stepper = PrimeGenStepper(2)],\n\
+ [tester = PrimeGenTester()], [event = pgen_nullev],\n\
+ [nsteps = 0], [ntests = RabinMiller.iters(START.nbits)]) -> P")