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**Studying for the LSAT / Re: Formal Logic Problem giving me trouble**

« **on:**April 20, 2007, 04:26:05 PM »

harvardorbust, I'm not understanding your inferences. I really only understand formal logic using the some and most trains as described in powerscore.

I understand how you got T ---->M<--m--S which includes T---->M<--s-->S (most includes inference some right?) and T---->M---->D

However, your final inferences I can't understand.

T<--s-->S (How did you get this inference? Starting at T, to then take a train away from M, I thought you could only use a double arrow, double not arrow, or all arrow because some and most arrows do not count because they do not necessarily include the entire group (page 322 of Logic Reasoning Bible).

I'm sorry for being all technical, but I can only understand formal logic using this method. If you could please help I would REALLY appreciate it.

Listen pal; you don't need a diagram to make an inference for this; we see that some S is older than M (that's our inference from "most"; but we also know that all T are older than M; but since some S is older than M and not all, we can assume that some S are not as old as T because all T are older than M and only some S are older than M;