Most Train Diagramming #5

[Iri]

Hi,

I have a question about question five on page 426 of the LR Bible.
The answer is M O. Can't you also infer that O M? Why is that not an answer as well?

Thanks!

[Dave Killoran]

Hi Iri,

Thanks for the question! Once you know that M O, then you do indeed automatically know O M. But, that "some" inference is an inherent inference that automatically follows from M O so I don't write those out (you will reach a point where you simply see those as part and parcel of the relationship, and thus it won't need to be written out). That's also why the directions specify that additive inferences are what we are looking for because those are the ones that result from combining relationships.

Please let me know if that helps. Thanks!

[Iri]

Okay, gotcha! Thanks for your help.