@JennaInch &

@Julia S.

thank you both! this makes sense and I see what I overlooked.

@Archer Heeren Try thinking like this:

If the necessity does NOT happen, it guarantees the FAILURE of the sufficient.

If the sufficient has happened, then it must mean the necessity also happened.

So in your example:

mastering conditional logic requires some amount of memorizing conditional indicators

If we do not memorize some amount of the conditional indicators then we will certainly fail to master conditional logic.

If we mastered the conditional logic then that means we must have memorized conditional indicators.

We cannot be sure that just because we memorized conditional indicators that we mastered conditional logic because there are other factors we must also do to achieve that goal. Memorizing is one of many factors. And we cannot say that if we did not master the conditional logic then it must mean we did not memorize the indicators because we could have done that successfully but failed to do some of the other things required.

Therefore:

memorizing indicators = necessary

mastering = sufficient

Hope that is helpful!

sufficient (S) = if S happens then X must happen

necessary (N) = if N does not happen then X cannot happen

Interestingly enough, S not happening doesn't mean X won't happen and N happening does not mean X will happen. Which I think would have made total sense to me if you hadn't spent a bunch of exercises teaching me how to use the contrapositives of everything with no care as to whether it's necessary or sufficient.

Number 4 feels wrong logically because if you know how to cast Herbivicus Charm, then you can mix plant material into garden soil and if you do that then the number of beneficial soil bacteria will increase. That connection feels logical, yet lawgic claims there's no connection. What am I missing?

@sjlutgen THANK YOU

@Anthonyelio7 that's a very good point, but you're probably better off with >5 instead as you are missing out on 5.2 seconds and anything else between 5 and 6.

@ZackDow that's correct. although the point of the indicators is not to write your own logic but to identify logic as written, so I'm not sure there's much value in writing versions of the claim with a sufficient indicator as opposed to the given prompt as is.

@cegattbs Just to add here after trying to think through this: Perhaps because "all cats" is not a singular but a category? Perhaps, members are individuals and therefore all cats cannot be a member but Garfield can as it is not a category but singular.

When visualizing it, "all cats" could technically be a dot within "Mammals" but it is actually a circle which would lead me to believe that C->M is the correct notation without reading the words.

Otherwise... not sure.

@blosciale Agreed! That's why my question was why is "all cats are mammals" translated to C->M instead of C^M?

Why does "all cats are mammals" not get translated in lawgic to C^M since it is stating that all Cats are members of Mammals and not "If cat, therefore mammals"?

@MalakAbusoud It took me a little while to find a good reason why we CAN'T substitute = for subscripts, but I finally have a good reason.

Essentially, if you use the = then you are saying that the relationship goes both ways: A=B leads you to assume that B=A. In the example in the video, Luke = Jedi but Jedi does not equal to Luke since there are Jedis that are not Luke. That is the only reason I have come up with why we use subscripts and not the equal sign.

A -> B means if A, therefore B (but you cannot assume if B therefore A from this)

A^B means A is a member of B (but you cannot assume B is also a member of A)

A=B means A is B and B is A.

Additionally, it could be messy in the video example if you did L=J because then you'd also use L=F and then from that, you can conclude that J=F and that is NOT TRUE. Hope that's helpful! I needed this answer myself.