# not sure what these basic FO symbols mean [closed]

I know some basic logic symbols, but i'm not sure what this formula means:

Fragment: http://i35.tinypic.com/14jt1n9.png

in particular, what is the subscript "1<=i

and the N with the A superscript. the multiple typefaces of "A".

this is beyond the basic and/or/exists/forall that i know in basic logic

is there a statement of this formula and its conditions in english words?

Thanks!

Updated: oops my bad, I should've read the part where they defined it!

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## closed as not a real question by Andy Putman, Yemon Choi, Victor Protsak, Robin Chapman, Qiaochu YuanAug 12 '10 at 7:41

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

Most of the definitions about $A$ in various fonts and ${\cal N}_r^{\cal A}$ you are looking for are at the top of page 3 of the article. The subscript $1\le i\lt j\le k$ just indicates which combinations of $i$ and $j$ are included in the conjunction.