PT 74 lg #23 Forum

[gojj11]

I still cannot get it.

As I know, contrapositive of ''If not K to T -> both A and B to T" is "either A or B is not to T(or Unless either A or B to T) -> K to T".

Why E is wrong?

I'm getting confused now

[leslieknope]

E says "either H or F to T" and translates to "/(H or M) to T ----> K to T". That's different than the language in the rule, which calls for a block. C says "/K to T---> FM to T", which, since FH are basically the same item due to the block language, makes it correct.

[gojj11]

E says "either H or F to T" and translates to "/(H or M) to T ----> K to T". That's different than the language in the rule, which calls for a block. C says "/K to T---> FM to T", which, since FH are basically the same item due to the block language, makes it correct.

thanks! got what I missed. really helped!

[Rook]

can someone explain to me how exactly you go about diagramming C? as far as i understand, whatever comes after the 'unless' is the necessary condition, and whatever comes before it is the sufficient negated. i dont know how to diagram this rule, as unless is the first word.

[leslieknope]

can someone explain to me how exactly you go about diagramming C? as far as i understand, whatever comes after the 'unless' is the necessary condition, and whatever comes before it is the sufficient negated. i dont know how to diagram this rule, as unless is the first word.

That's actually the trick to diagram the contrapositive. I personally find it easier to think of unless (and without/except/until) as negate sufficient indicators. You take whatever is after the unless, negate it, and that's your sufficient condition. The other term is the necessary condition. So "Unless K is in T, F and M are in T" becomes "/K to T---> FM to T."

[Rook]

can someone explain to me how exactly you go about diagramming C? as far as i understand, whatever comes after the 'unless' is the necessary condition, and whatever comes before it is the sufficient negated. i dont know how to diagram this rule, as unless is the first word.

That's actually the trick to diagram the contrapositive. I personally find it easier to think of unless (and without/except/until) as negate sufficient indicators. You take whatever is after the unless, negate it, and that's your sufficient condition. The other term is the necessary condition. So "Unless K is in T, F and M are in T" becomes "/K to T---> FM to T."

i see...thanks for the explanation!