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:<code><nowiki><math>a \sin \theta = a \operatorname{sin} \theta \,\!</math></nowiki></code>
produces
:<math>a \sin \theta = a \operatorname{sin} \theta \,\!</math>.

This way, <code>\operatorname</code> is useless, being essentially synonymous with <code>\mathrm</code>:
:<code><nowiki><math>a \mathrm{sin} \theta = a \operatorname{sin} \theta \,\!</math></nowiki></code>
:<math>a \mathrm{sin} \theta = a \operatorname{sin} \theta \,\!</math>.

For now, I use the workaround
:<code><nowiki><math>a \sin \theta = a\,\operatorname{sin}\,\theta \,\!</math></nowiki></code>
:<math>a \sin \theta = a\,\operatorname{sin}\,\theta \,\!</math>.
:<code><nowiki><math>\phi = \operatorname{artanh}\,\beta \,\!</math></nowiki></code>
:<math>\phi = \operatorname{artanh}\,\beta \,\!</math> (notice the <code>\,</code>s).

<code>\bmod</code> has the same problem:
:<code><nowiki><math>n \bmod 2 \qquad n\,\bmod\,2 \,\!</math></nowiki></code>
:<math>n \bmod 2 \qquad n\,\bmod\,2 \,\!</math>.