Commentator covers accident which occurred "last week". This means that it has been a week since this wreck and Acme has already been asked about why their new trains have this defect fixed (i.e., new trains already exist at the time commentator covers this accident). Given that Acme's new locomotives were manufactured probably some time prior to the accident (I just can't imagine they became aware of the defect and changed it in their new trains in a week time), Acme should have removed knee-level switches on purpose some time prior to the accident. Why? They knew it was not safe long time prior to the wreck and fixed it.

Long story short: My understanding is that at the time of the accident they had both old (with defect present) and new (with defect fixed) locomotives.

Hope it helps, sorry for being wordy

AC D is also necessary. If no steel plant has electricity as a "primary" source of energy, then plant will not have costs "greatly" reduced by converting heat into electricity. Instead, steel plant will end up with only a modest reduction since it does not primarily rely on electricity. For me both C and D are correct, and a choice between them is almost arbitrary.

Could it be that AC C baits us to make an assumption about why the television program showed more nay-sayers?

Exmple of such assumption would be that TV program's motivation was purely commercial - they showed more emotional opponents of freeway to get more views rather than because they are biased (another unwarranted assumption about emotional interviews->more views)? Would it help to undermine "bias" conclusion?

There seems to be a reference "such doubling in a computing speed". Which "such" doubling in a computing speed? Doubling which occurred for the last decades together with doubling in number of transistors.

We know that for several decades (of which "mid 1990s - into next decade" is a part) each 18 months doubling in number of transistors occurred simultaneously with doubling in computing speed.

Whether doubling in number of transistors was the sole cause of doubling computing speed or one of many causes - we don't know. -> A can not be properly inferred.

However, since during out target period each doubling of computer speed was accompanied by both doubling in costs and number of transistor, we can infer D.

At least this is how I got it. Please feel free to correct me.

Same question.

If the rule stresses out that blackout will definitely occur if there is no HWA, then why not translate it into Lawgic as BO->/HWA.

I tried to come up with my own examples "I will catch Pikachu unless he is on vacation". According to the above, it should be translated as "/catch->vacation" and "/vacation->catch", but why we can not write it down as "catch->/vacation" and "vacation->/catch"?

#help

Hi Gigiyaya,

I understood it like this.

The following statement - "Amidala cannot deliver her speech unless the attempt to assassinate her fails" - contains Negate Sufficient indicator, which is "unless".

Therefore, breakdown of this statement is as follows:

#1:Amidala can deliver speech ("cannot" is negated into "can")->attempt to assasinate her fails

#2:Attempt to assasinate Amidala did not fail ("fail" negated)->amidala cannot deliver her speech

Paragraph provides us with the information that attempt to assasinate Amidala failed, which is a necessary condition presented in #1. However, the fact that this necessary condition is satisfied does not guarantee us that Amidala can deliver speech. There can be other reasons why she will not deliver speech. Maybe she changed her mind or forgot the words. We simply do not know because the paragraph did not give us any sufficient conditions which if satisfied would guarantee that she will deliver her speech.

Therefore, we can not say that "the vote to grant the Chancellor emergency powers will not pass".

If the paragraph mentioned that "if the attempt to assassinate her fails, then Amidala will deliver speech" would guarantee us the result because it contains sufficient condition "if the attempt to assasinate her fails" ("if" is a Sufficient condition indicator).

I'll leave some of my observations in case it helps someone.

I've noticed that when dealing with necessity issues, it is impossible to have a structure like this: "/x->y", unlike with sufficiency conditions.

For instance, if you take this statement from item 4.1 - "Imperial palaces in the Tang dynasty never had glass windows" - you can not produce any structure alike "/x->y" because the rule is simply silent on those. Here are some proofs:

"If its not the imperial palaces in the Tang dynasty, then there are glass windows"; "If there are no glass windows, then its imperial palaces in the Tang dynasty". Both these statements are incorrect. You can tell it by either applying some cognitive efforts to imagine if these are true, or you can simply spot that you are not dealing with sufficiency conditions, and hence structure "/x->y" is not possible. It is actually only vice versa (i.e., "y->/x") that is possible.

I hope it does not confuse anyone and please let me know if you disagree.