LR Diagramming

[marieallen]

So, I've gone back and forth on various diagramming issues from the 2017 LR Bible Chap 6 and this is what I've come up with:

Linkage: - c d; d e means c e
"Either / or": means 1 to both may occur but at least 1 must occur: -g h; -h g; gh
"Either / or but not both": means 1 must occur: -i j; -j i; j -i; i -j
"Either...than": means 1 variable compared to both of the other 2: (I don't know how to draw k with a double branch to l & m but see 2017 pg 50 of LG Bible re Sequencing Rules.)
"If and only if": means both may occur or not occur but 1 cannot occur: t u; t u
"If.., then not...": 0 to 1 may occur but not both: v w

Please correct anything I diagrammed incorrectly! Thanks.

[Jonathan Evans]

Looking good, Marie Allen!

A couple things: you're not negating c in the first conditional, right? c d; d e leads to c e.

That "gh" in either/or, that just means g or h or g and h. Is that what you mean? You're conditionals are valid.

Your either/or but not both looks good.

That "either...than" business really doesn't require diagramming. It's just something to be aware of. It's a kind of syntax in which "or" is inclusive. I like ice cream better than either pickles or anchovies. Okay, cool. I like ice cream better than pickles, and I also like ice cream better than anchovies.

"If and only if" means that both conditions imply each other. You win at tic tac toe if and only if you get three in a row. Both conditions are sufficient to guarantee the other. Both conditions are necessary for each other.

If you get three in a row, you win. If you win, you get three in a row.

If you don't get three in a row, you don't win. If you didn't win, you didn't get three in a row.

Either both conditions happen or both conditions don't happen. There is no way that one condition occurs and the other doesn't.

You've got the double not arrow notation right.

Good job!

[marieallen]

Thank you - everyone at Powerscore is always so positive and encouraging!!! Thanks again!