Hello again Presley!
The 'button' phrasing is to help reinforce the one-directional power of conditional statements. By definition, a conditional statement is a hypothetical rule that stays dormant until activated.
For example, take the claim: If Steve goes to the grocery store, he will buy beer. It is Memorial Day Weekend after all
Diagrammable as: SGS ---> BB
That rule doesn't actually let us guarantee that Steve will be buying beer, we just know a condition that, if met, would guarantee that he does.
So, by circling the sufficient condition (always the left side of the equation) and making it a "button" we can know exactly what situation can bring the rule to life. As soon as we know for a fact that Steve is at the grocery store, the button is activated and the rule guarantees that he will buy beer.
Like in any conditional statement, the arrow and the logic only go from left to right. Knowing that Steve bought beer has zero implication on where he was, he could have been at a liquor store or a bar. In this game, Norton being in 5th has zero impact on where Lalitha could or could not be, much like if you accept that Texas ---> USA would not let you know much about in which state someone lived if all you knew was that they were in the USA.
In class I always draw the circles/buttons around every sufficient condition to make it more visually obvious what we're looking for to activate a conditional rule in a game.
In this particular game, the rule states that if P is not second, he must be fifth, and of course the contrapositive states that if he is not fifth, he must be second.
That situation leads to a 50/50 hinge that the game depends upon, and in using my Coin Toss with Consequences strategy (blog post here:
https://blog.powerscore.com/lsat/whats- ... gic-games/ we can make two templates.
When Patrick is in 5th place, that activates the button from the contrapositive of rule 3, as of course when Patrick is in 5th, that means Norton is not. So, Norton not being in 5th ensures that Lalitha cannot be in third.
Contrapositives are a mandatory part of proper LG set ups and inferences, as they have the exact meaning as the original rule and the LG creators constantly reward those of us who understand the concept, consequently punishing those who don't.
It seems that your confusion with rules 3 and 4 stems from a larger issue with conditional reasoning in general, so I would definitely recommend you go back and review the book and video from Lesson Two, which covers this (very tricky at first!) concept in much further detail.
I hope that this helps, and I hope to actually get to chat with you during one of our last few live class meetings!