In other words, in practice, ""non sequitur"" refers to an unnamed formal fallacy. He commonly used Frank Stallone as a non sequitur punchline. This, incidentally, is precisely the meaning of the Latin phrase "non sequitur" in logic. This sort of non sequitur is also called affirming the consequent. The third argument, unlike the first two, contains no "non sequitur" that Feinberg can see. More specifically it is also a form of non sequitur. To bring the civil rights struggle into this is just a non sequitur. This principle was called "partus sequitur ventrum". This principle called "partus sequitur ventrum" was adopted from Roman law. They had three children born into slavery under the "partus sequitur ventrem" principle. Other practical grammar compression algorithms include Sequitur and Re-Pair.