Say someone makes a thread, and then the author makes a post in that same thread. In the post, the author uses 2+2=5 to justify one of his statements.
If I provide a logical proof of why 2+2=5 is not a sensible statement, is that out of bounds in the discussion. Because it is technically off topic and it is not connected to the original post, even though it is a direct response to one of the authors posts in the same topic. If the author says 2+2=5 in one of his posts, it is offtopic to try to disprove that 2+2=5, because it is not a direct response to the original post, but one of the author’s later posts in that same topic.
Also, if I have a few typos, or have subliminal grammar mistakes, then that nullifies my point that 2+2 isn’t 5, because if I forget to put a comma or have incorrect spacing between words, the important thing is that 2+2=5, and unless I can say with perfect grammar that 2+2 does not equal 5, then 2+2=5 and if I comment that 2+2 does not equal 5, there is a risk of Derailed Train threads.
I feel like I made a mistake, I shall sit in the corner with my dunce hat. From now on, unless the topic is specifically about whether 2+2=5, I should know better than to derail the thread by saying that 2+2 does not equal 5, and it is impolite to correct the author if he says 2+2=5, unless the topic is directly about 2+2=5.
Also, if I provide a lengthy logical proof, but I put a small ad hom at the end of it I am an ad hommer, but if the other person never provides any logical proofs and only ad homs, then he is wise of years, and I am a sad, pathetic dunce, and I shall sit in the corner.