unless signifier

Hello @Maria, Keep in mind that creating a contrapositive of an if/then statement maintains the exact same meaning. You may have diagrammed something differently, but you can diagram as you please as long as it is logically sound. I'll go through the premises of this question and maybe that will clear things up. Premise: If you climb mountains (CM) you will not live to a ripe old age (not ROA) CM - - - - - - > not ROA ROA - - - - - > not CM (contrapositive) Premise: You will be bored (B) unless you climb mountains (CM). not CM - - - - - -> B not B - - - - - - - -> CM (This is probably where you put CM as a necessary condition. Do you see how that is totally fine as long as you can create a proper contrapositive?) Premise: If you live to a ripe old age (ROA), you will have been bored (B). This last statement links some of our previous premises together. It is a true statement, something that we can logically conclude based on the passage. ROA - - - - - > not CM - - - - - - > B

Hey, I narrowed down the two questions to C and E by the wording used. I was also able to diagram both C and E. However, I diagrammed C as: WFC-----> not IGP IGP ------- > not WFC (contrapositive) not CD ------ > WFC not WFC ------> not CD so my contrapositive chain looked like IGP----->not WFC-----> not CD However, in the diagram review example, she does not do not CD, instead she writes how NCD to represent neglect. Doing so, it makes a difference in the chain. Why is there a difference between NCD and not CD to the chain?

The thing I am learning well in these S&N questions is the "but.....unless" statements where we "negate" the sufficient to be logically sound. I was not doing that before!