# Vertical “fractions” with more than 2 parts

Standard FractionBox syntax allows only 2 arguments and creates 2-part fraction for numerator and denominator.

Is it possible to draw similar construction, but with more than 2 parts? Some sort of column with separators only between inner parts?

The following code

Column[{"x", 200, Integrate[Sin[x^2], x]}, Alignment -> Center, Dividers -> Center]


draws best what I found but it does dividers of similar length in entire column. I would like dividers to accommodate two adjacent parts only.

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Yes, I have custom expressions which I want to have such custom syntax. – Suzan Cioc Mar 4 '13 at 15:02
I'm not totally clear on what you want. Could you describe why nested FractionBoxes aren't suitable? For instance, Fold[FractionBox, x, Range[5]] // DisplayForm – Oleksandr R. Mar 4 '13 at 15:10
@Oleksandr I think the problem with that is the shrinking point size. – Mr.Wizard Mar 4 '13 at 15:14

Interesting question. I don't have much experience with this sort of thing so I imagine there is a better way but this is what I could hack together at the moment:

frac[lst_List] := Column[
Column /@ Partition[Riffle[lst, \[HorizontalLine]], 2, 2, -1, {}],
Alignment -> Center, Spacings -> 0]

{"x", 200, Integrate[Sin[x^2], x]} // frac


Here is another approach, probably closer to "correct":

frac2[lst_List] :=
Style[Fold[FractionBox, #, {##2}], ScriptSizeMultipliers -> 1] & @@
(ToBoxes@Style[#, ScriptSizeMultipliers -> 0.71] & /@ lst) // DisplayForm

{"x", 200, Integrate[Sin[x^2], x]} // frac2


I am assuming that you want expressions at any tier of the notation to be the same size. If you are fine with them shrinking as they go up then a much simpler form can be used without Style and ScriptSizeMultipliers:

frac3[lst_List] :=
Fold[FractionBox, #, {##2}] & @@ (ToBoxes /@ lst) // DisplayForm

{"x", 200, Integrate[Sin[x^2], x], Integrate[Sin[x^2], x]} // frac3


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Thanks a lot! Will learn of your examples! First ones are better (without shrinking). – Suzan Cioc Mar 4 '13 at 15:55
@Suzan You're welcome, but you may want to leave this question open (no Accepted answer) for a while longer. I am hardly an expert at output formatting. – Mr.Wizard Mar 4 '13 at 15:59
Ok will wait for other points... – Suzan Cioc Mar 4 '13 at 17:07
For ScriptSizeMultipliers less than one you might like to also add ScriptMinSize. Also ScriptLevel -> 1 may or may not be preferrable. The OP might like to try it out. – Mike Honeychurch Mar 4 '13 at 22:11
@Mike Thanks for the tips; I'll try them out later. Or, you could post your own answer if you prefer. – Mr.Wizard Mar 4 '13 at 22:14