12 comments

  • Friday, Feb 06 2015

    @catherinem8843 yes

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  • Friday, Feb 06 2015

    I take it as If it is X and it builds Y, it must build Z.

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  • Friday, Feb 06 2015

    Ahhh I see. So we have two conditions for the conditional.

    If you have Y AND /Z then you don't have /x.

    Which is what you said:

    Y & /Z ---> /X

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  • Friday, Feb 06 2015

    @mahdiall408 I don't think so. think of it as no X builds Y without(but not) building Z

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  • Friday, Feb 06 2015

    Wait, I'm actually confused lol. I understood this statement to mean two things:

    1) no X builds Y (Y --> /X)

    2) no X does not build Z ( Z --> X)

    Y --> /X

    /X --> /Z

    -----------

    Y --> /Z

    Is that not right? lol

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  • Friday, Feb 06 2015

    eh its similar... and I like the wording you used there @catherinem8843

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  • Friday, Feb 06 2015

    It is saying that if X builds Y, then it must also build Z take out the negative language on this one.

    (X-->Y)--> (X-->Y&Z)

    The contrapositive of the statement is, if X does not build Z then it does not build Y.

    I hope this helps a little.

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  • Friday, Feb 06 2015

    @jinadarcy0610262 Okay, that makes much more sense for me - I saw both as possibilities but I thought that

    "X can build Y and Z but cannot build Y if it doesnt also build Z"

    would be written as "No X builds Y, but not Z". And with that, time for some coffee! Thanks for the clarification though; I appreciate it!

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  • Friday, Feb 06 2015

    @alexandershort4891 idk, that makes it look like X can't build Y and Z which isn't how I see it. I see it as X can build Y and Z but cannot build Y if it doesnt also build Z

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  • Friday, Feb 06 2015

    jdawg's approach was the other route I imagined possible... but I hesitated with that approach only because the grammar trips me up with this particular phrasing (aka, the lack of a comma). Good to know!

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  • Friday, Feb 06 2015

    Hey Alex - how's it going? Long time no see - we should meet up sometime. I would look at this statement as "X builds Y, but not Z", with the 'No' negating all elements that follow.

    I understand "X builds Y, but not Z" much more easily, and would write it as a single X with two arrows, one to Y and another to ~Z.

    If there is no comma in the statement, I'd have to assume the "No" at the beginning applies to both elements.

    So, "No X builds Y":

    X -> ~Y

    And "No (X builds Not Z)"

    (X -> ~Z)

    ~X -> Z

    Ultimately getting:

    X -> ~Y and ~X -> Z

    Although, admittedly, I'm certainly uncertain about my approach in this case.

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  • Friday, Feb 06 2015

    if Y & /Z -> /x (i think)lol took me a minute to make sense of that, its saying X cannot build Y without building Z too

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