Anatomical bilateral symmetry is a common trait. It follows, therefore, that it confers survival advantages on organ...
mprezzyFebruary 16, 2020
Diagramming
I am having difficulty understanding the diagramming in the video. The video is explaining: not CSA -> not CT and it's contrapositive. When I try this alone I am not negating the variable. I am writing them as it, sentence by sentence. This is how I wrote it: CT -> CSA and its contrapositive. I understand that either way I write it I am looking for the valid contrapositive argument structure that is in common; however, I am concerned because if in looked for that correct answer using my diagram the variables are crossed out (in contrapositive form) but if I use the method in the video they are not. The fact that they are not identical, (meaning the contrapositive forms are not the same) does that matter or is it enough that they both are structured in a valid contrapositive form. Please help.
Replies
Create a free account to read and
take part in forum discussions.
As long as you got to the right answer, then your method was totally fine. Remember that a contrapositive carries the exact same logic as its positive counterpart. They are interchangeable. The only reason to use one over the other is personal preference. As long as you are properly making contrapositives, and you are able to follow the logic, then there is no problem. Do you remember your missing premise drills, where both versions of the correct answer are listed?
My guess is that it was expressed that way in the video because they wanted to write the premise first (The second sentence).
