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<div class="moz-cite-prefix">Carlos wrote:<br>
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<blockquote type="cite" cite="mid:CAKgLwh6ihNGPRmytBWuv2wbXK7Mh4CL_DXAYut3rycoaK_0+4g@mail.gmail.com">
<div dir="ltr">Philip and David, and list in general. The message 'Extra alignment tab has been changed to \cr' is as misleading as the code from tabular environment, because it does absolutely nothing but implying that a \cr has been applied and hence, a newline
follows thereof. </div>
</blockquote>
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What leads you to believe that (1) \cr, and (2) a newline, have any connection whatsoever ?<br>
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<blockquote type="cite" cite="mid:CAKgLwh6ihNGPRmytBWuv2wbXK7Mh4CL_DXAYut3rycoaK_0+4g@mail.gmail.com">
<div dir="ltr">if as the TeXbook says, TeX looks only for \cr commands, from which I infer is thus expanded,
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Why would you infer that \cr is expanded ? It is a primitive, and does not occur in the list of primitives that "are expanded whenever expansion has not been disabled" [p.~212
<i>et seq.</i>].<br>
<br>
<blockquote type="cite" cite="mid:CAKgLwh6ihNGPRmytBWuv2wbXK7Mh4CL_DXAYut3rycoaK_0+4g@mail.gmail.com">
<div dir="ltr">and '&', '#' and so forth and the glue in '\tabskip' which is scanned as usual - note the macro expansion of \cr,
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There is no "macro expansion of \cr"; \cr is a non-expandable primitive (as above).<br>
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<blockquote type="cite" cite="mid:CAKgLwh6ihNGPRmytBWuv2wbXK7Mh4CL_DXAYut3rycoaK_0+4g@mail.gmail.com">
<div dir="ltr">then it follows that TeX under your tabular environment must have missed the macro expansion of \cr.
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Sigh. There is no "macro expansion of \cr".<br>
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<blockquote type="cite" cite="mid:CAKgLwh6ihNGPRmytBWuv2wbXK7Mh4CL_DXAYut3rycoaK_0+4g@mail.gmail.com">
<div dir="ltr">One thing is a misplaced alignment tab character '&' and and another entirely different is extra alignment tab has been changed to '\cr.' Two different things and by now you ougth already know.
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A misplaced alignment tab character '&' might result from (for example) the usage of '&' (with its default catcode) outside of an alignment. One '&' too many within an alignment, however, is not "misplaced", it is "an extra alignment tab".<br>
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<blockquote type="cite" cite="mid:CAKgLwh6ihNGPRmytBWuv2wbXK7Mh4CL_DXAYut3rycoaK_0+4g@mail.gmail.com">
<div dir="ltr"><br>
If you were to say and this is from the TeXbook<br>
<br>
\settabs 2 \columns<br>
\+ this material is flushed right & \cr<br>
this material is set centered & \cr<br>
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You'd have the expected 'misplaced alignment tab character '&'<br>
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I am not a LaTeX user, but I would not expect \begin {tabular} to involve \settabs; I would expect it to involve \halign. Therefore, unless I am mistaken in this belief, bringing \settabs into the discussion is completely irrelevant.<br>
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<blockquote type="cite" cite="mid:CAKgLwh6ihNGPRmytBWuv2wbXK7Mh4CL_DXAYut3rycoaK_0+4g@mail.gmail.com">
<div dir="ltr"><br>
But lo and behold if you were to have the same under your environment. Your implementation. Silly environment as it is.<br>
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look closely for posterity<br>
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\begin{tabular}{cccc}<br>
\hbox to 2cm {una} & prueba && \cr<br>
para ver &&&& \cr} & & & & % look at the closing brace and hence the missing \cr.<br>
\end{tabular}<br>
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I have no idea what this code is intended to accomplish, but if I feed it into LaTeX (with a suitable wrapper) I am told :<br>
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<blockquote type="cite">! Extra alignment tab has been changed to \cr.
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;">
<recently read> \endtemplate </p>
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as I would expect.<br>
<br>
Philip Taylor<br>
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