<div dir="ltr">As an example, when I run mpost -tex=latex <a href="http://vafa.mp">vafa.mp</a>, I get this error:<br><br>)fatal: Command failed: latex mpf0LcjR.tex; see mpxerr.log<br>>> <a href="http://mpdefs.mp">mpdefs.mp</a><br>
>> mpdefs.mpx<br>! Unable to make mpx file.<br>l.6 newBox.a(btex<br> apples\strut etex);<br><br>but if I delete \selectlanguage{farsi} from <a href="http://vafa.mp">vafa.mp</a> and the run mpost -tex=latex <a href="http://vafa.mp">vafa.mp</a>, there is no problem.<br>
<br>Then I come and add the deleted \selectlanguage{farsi} to <a href="http://vafa.mp">vafa.mp</a> and run mpost -tex=latex and strangely this time, there is no problem. Why?<br><br clear="all"><br>-- <br><div dir="ltr">If some one say: "You divide ten into two parts: multiply the one by
itself; it will be equal to the other taken eighty-one times."
Computation: You say, ten less thing, multiplied by itself, is a hundred
plus a square less twenty things, and this is equal to eighty-one
things. Separate the twenty things from a hundred and a square, and add
them to eighty-one. It will then be a hundred plus a square, which is
equal to a hundred and one roots. Halve the roots; the moiety is fifty
and a half. Multiply this by itself, it is two thousand five hundred and
fifty and a quarter. Subtract from this one hundred; the remainder is
two thousand four hundred and fifty and a quarter. Extract the root from
this; it is forty-nine and a half. Subtract this from the moiety of the
roots, which is fifty and a half. There remains one, and this is one of
the two parts.<br><br><b>Muḥammad ibn Mūsā al-Khwārizmī</b></div><br>
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