If it is required that the sequence produced by successive calls of random/1 be reproducible, seed(Seed) can be called to initialise the calls with the integer Seed. Do not assume that the same sequence will be produced for the same seed on different platforms, because the C library's implementation of random() may differ.
Success: ?- random(N1), random(N2). N1 = 464880439 N2 = 285401533 yes. ?- seed(1), random(N). N = 2078917053 yes. ?- seed(1), random(N). N = 2078917053 yes. Fail: random(12345). Error: random(12.34). (Error 5).