Diagraming unless

[EarlCat]

I am working thru the LRB and got a little caught up on the conditional chapter. Any tips on how to always get the
sufficient and necessary straight 100% of the time other than memorize every preceding indicator?

You should be come familiar enough with the concepts of sufficient and necessary so that you can determine which is which even if given an indicator you're not familiar with or haven't memorized.  Don't just read through your book and remember that a certain word means necessary.  Figure out WHY, so that you can make that determination on future words.

[Variant]

I am working thru the LRB and got a little caught up on the conditional chapter. Any tips on how to always get the
sufficient and necessary straight 100% of the time other than memorize every preceding indicator?

Where do you usually go wrong?

[OJ]

Don't have thugs wave guns around in a hotel room in Vegas for sports memorabilia.  It's really cold in here and they wont give me a pillow.

Is that you, Cliff? Are you really that bored?

Who's Cliff, is he related to Elvis?  I'm a running back stuck in a 7-by-14 concrete room, they wont turn off the light and dinner sucked.


 

[Ron Goldman]

I'm a running back stuck in a 7-by-14 concrete room, they wont turn off the light and dinner sucked.

And you think you've got problems???

[proof18]

Does unless work the same way as except, without, and cannot? Are there any other words that serve the same function as unless (where you negate the sufficient)?

Thanks.

[nevdash]

Does unless work the same way as except, without, and cannot? Are there any other words that serve the same function as unless (where you negate the sufficient)?

Thanks.

It's logically equivalent to "or."

[EarlCat]

Does unless work the same way as except, without, and cannot? Are there any other words that serve the same function as unless (where you negate the sufficient)?

Thanks.

A unless B is the same as A without B in the sense, they both work as, "if not."  The others I think we need context b/c they can be phrased several ways that might change the outcome.

[GCoop.]

I am working thru the LRB and got a little caught up on the conditional chapter. Any tips on how to always get the
sufficient and necessary straight 100% of the time other than memorize every preceding indicator?

Think about all the possibilities.

I'm not going to the movies unless it's raining.

Well, there are four things you might know:

I'm at the movies.
I'm not at the movies.
It's raining.
It's not raining.

Look at each of those, and look again at the statement.

What do you know if I'm at the movies?  Well, since I won't go to the movies unless it's raining, if you see me at the movies, it must be the case that it was raining.  Thus:

Movies -> Raining

What do you know if I'm not at the movies?  Well, the rule says I won't go to the movies unless it's raining, but it doesn't say that I HAVE to go to the movies if it rains, so I don't know anything if I'm not at the movies.

You can always reason these things out and word them into if/then statements and diagram them easily.  Just think through the possibilities and play them against the meaning of the conditional statement. 

Eventually it becomes second nature.