Hey!

Can someone please explain how to interpret rules 3 and 4 of this LG? (PT B, S2, G2)

3: "If y is not in, then either L or O, but not both are in"

How I interpreted this rule:

Not Y --> L or O

Contrapositive:

Not L and Not O --> Y

4: "If it's not the case that the park contains both L and O, then it contains F and S"

How I interpreted this rule:

Not L and Not O --> F and S

Contrapositive:

Not F or Not S --> L or O

In the explanation video, JY has a world where L, O and Y are all in, and I don't understand how we got there. I'm sure I'm missing some kind of bi-conditional lesson, or something. Did he just "negate" rule 3 by just the wording like: "if L and O are both in, Y is in," and that's how we got a possible world where L, O and Y are all in? Please help me lol

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