(topology, of a map) Homotopic to a constant map.

plural of null hypothesis

(mathematics, stochastic processes, of a state) persistent with infinite expected return time.

(mathematics, stochastic processes, of a state) Recurrent with infinite expected return time.

(mathematics, stochastic processes) The quality of being null recurrent.

plural of null modem

(computing) A means of directly connecting two pieces of equipment (computer, printer, etc.) using a serial cable.

plural of null infinity

(computing) A device file, present in Unix and Unix-like operating systems, that discards all data written to it and yields no output.

plural of null sign