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+1 vote

The command \frac{1}{2}(x+y) yields 1/2(x+1)^-1. Introducing a space before the parenthesis, \frac{1}{2} (x+y), gives the correct result 1/2(x+1).

in Bug reports by (330 points)

1 Answer

+2 votes

That is essentially because I used to write a lot of


type of things, and those then at first instance become


In general, the parser does not know about the meaning of operators, and so it cannot know whether \frac only takes 2 arguments, or more.

by (71.6k points)

That is counter intuitive:

  • a fraction with more than two arguments
  • space sensitive LaTeX parsing
  • round parentheses parsed as argument parentheses I would prefer a separate command for fractions with multiple arguments for your use case.

1/a/b/c = 1/(abc) ?

Parsing is space-sensitive in many places, e.g.

 a (b+c) versus  a(b+c)

and this also shows that arguments have round parenthesis. In general, LaTeX is simply not enough to determine what you really mean, you need to have some additional guidance.

I agree though, in principle, that there may be things that are not optimal. Maybe one day when all urgent issues are off the table I can go back and look at this, but at the moment there are more pressing things to worry about ;-)