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Q. Hi. Is it acceptable to begin a sentence with a mathematical variable? I had been going by the thinking that since one spells out a number when beginning a sentence, one would not begin a sentence with a variable or other mathematical expression. However, I have seen numerous such occurrences in journal articles, leading me to think that copy editors would have made corrections if this were considered a stylistic error. I have not been able to find any advice about this, and so I was wondering about your stance on it. Thank you.
A. In general, a variable or other mathematical symbol should not begin a sentence. For examples and suggested remedies, see CMOS 12.7.