# Re: [NTG-context] two nested \mathbin command changes spacing

On 4/30/2018 6:50 PM, Ulrike Fischer wrote:

In the following document the second a is much nearer placed to the
V:

\starttext
$V \mathbin{a} W \qquad V \mathbin{\mathbin{a}} W$
\stoptext

(in the second case an italic kern seems to be missing)

Can one avoid this side effect of nested \math-command? When
building symbols it is not always easy to avoid such nestings.

this is again a side effect of bad glyph boundingboxes


anyway, the tex engine collapses nested ord nodes so i generalized that in the upcoming engine

\mathflattenmode \numexpr
0  % off
+  1  % ord
+  2  % bin
+  4  % rel
+  8  % punct
+ 16  % inner
\relax


so you can get rid of nested same-class (actually this is only done when no super or subscript) .. as a side effect you get a sequence of math char nodes and that will then listen to the other italics enforcing flag (for fonts with weird character boundingboxes)


i didn't test side effects but at least we can influence it (the default is of course 1 which is what tex naturally does)

Hans

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