lots of coffee lol

Yep same here

Wouldn't E be contradictory... I may be mistaken here, if anyone can elaborate on the logic of this for me I would really appreciate it. If the passage says "the killer whales do not seem to behave differently around running boat engines" and E says "Killer whales would probably be more successful in finding food if boats did not travel through their habitats." then wouldn't this be contradictory to the claim in the passage?

Agreed. This was difficult to understand. To clarify: if "know‑m→/good AND know→violinist at philharmonic" then the "most" arrow and "sufficiency/necessity" arrow cannot be used the same way the "some" arrow can be used. I.e. can't group together concepts and say "some of those who are /good are violinists at the philharmonic" that share a sufficient condition ("know") because of the unidirectionality of the arrow?

I am hoping to get clarification on this as I can't remember if it was spoken to in the lessons on most/some etc. If the argument says: "Most of Harry Potter's friends are wizards," could I write the contrapositive as "most people who are not wizards are not harry potter's friends" ?

In the second example within this lesson it says "Most of Harry Potter's friends are wizards. Most people who are not his friends are not wizards" so (HPF ‑m→ W) (/HPF ‑m→ /W). I am assuming this is a standalone clause and not the contrapositive of the former argument. If anyone can confirm this I would really appreciate it.

Could it have been /A->S and /S ->A? I'm curious why "killing" was considered as the necessary condition.

Same here! I was confused by the same thing.

For Q4:

Farmers do not know their income for a given calendar year until tax returns are calculated and submitted the following April.

I answered

/knowing income for a given year -> /tax returns calculated

tax returns calculated -> knowing income for a given year

I confused the sufficient condition and necessary condition, any elaboration on what makes the "knowing income tax" the sufficient condition and "tax returns calculated" the necessary condition?

Question about Q2, wouldn't every time technically be the same thing as "always?"

Every time a NASA program pushes the frontiers of humanity, our collective confidence swells.

So if it is that this happens every time, wouldn't it be a necessary condition? I might be overcomplicating it for myself but I just wanted to get some clarity regarding the wording. Thank you in advance!!

#feedback I'm not sure if this comes up in later lessons but I'm trying to come up with examples using the other logic indicators (i.e., every, all, any), but I'm struggling a bit to see how these can come into use for sufficient conditions. It would be really helpful to see some sample sentences within this video or the except below.

I answered similarly, is anyone able to provide feedback?

In question 4, why wouldn’t the “in that” be considered as a referential to the later part of the sentence “ the lender sets the terms of its dealings with the borrower. “

Does it only qualify as a referential if the words are spaced out by a certain amount?