[Tex/LaTex] Why does \cal{M}_n give “M>”


Why does \cal{M}_n give “M>” in parts of my LaTeX file and works correctly in other parts?

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Best Answer

The correct syntax is


The \cal command was used in LaTeX 2.09 and has been obsolete since the release of LaTeX2e (1992). It worked as a font change declaration rather than a command with argument, so the right way would have been

${\cal C}_n$

which is quite confusing.