Always raise plus sign in text

Question

I have a lot of places in my dissertation where the plus sign appears surrounded by capital letters in text, e.g. NNLL+NNLO.
The problem is that by default, the + is aligned so low vertically, that among caps it looks badly aligned.
By playing around with the \raisebox, I found that it looks quite a bit better if raised by 0.25ex, and still looks fine with lowercase letters, even in situations like a+j.
Is there a way to change the default behavior of the plus sign to always appear raised in text?
I don't want to change what happens in the math mode.

I suppose a potential solution might be to globally substitute raw + by \raisebox{0.25ex}{+} (modulo the issue with space swallowing) or to make latex use a different font for rendering the +.
I just don't know if that's even possible.

Reporting on what I implemented based on the answers.
Here's the command I came up with that also accounts for bold and allows typesetting of two consecutive raised spaces with \++.

\makeatletter % https://tex.stackexchange.com/a/31660/35990
\newcommand*{\IfbfTF}{% detect bold font
  \ifx\f@series\my@test@bf
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi
}
\newcommand*{\my@test@bf}{bx}
\makeatother
% https://tex.stackexchange.com/a/567256/35990
\newcommand{\textplus}[1][+]{\raisebox{% font-independent height
  \dimexpr(\fontcharht\font`X-\height+\depth)/2\relax
}{\IfbfTF{$\bm{#1}$}{#1}}}
\ExplSyntaxOn
\NewDocumentCommand+{}{
  \peek_charcode_remove:NTF + {\textplus[++]}{\textplus[+]}
}
\ExplSyntaxOff

\peek_charcode_remove:NTF requires the expl3 package.

I am not sure what you mean by "issue with space swallowing" ? + and \raisebox{0.25ex}{+} (and my suggested \+) all have the same behaviour with respect to surrounding white space. — David Carlisle, Oct 17 '20 at 22:31
If you define \newcommand\myplus{+} and then write \myplus a, it is rendered as '+a' without a space. I assumed the same would also happen for \newcommand\+{+}, which seems to not be the case. Can anyone explain why? — SU3, Oct 17 '20 at 23:37
I also assumed that however a global substitution of + would work, it would internally rely on a new command definition and thus have the usual space problem. I clearly don't understand when space are swallowed and when not. — SU3, Oct 17 '20 at 23:42
not sure what you mean by a global substitution, you mean replacing + by \resizebox{}{} in your editor? Yes that would work as well. — David Carlisle, Oct 17 '20 at 23:45
Like I wrote in the question, I don't know if that is possible in latex, but one could imagine some mechanism that would allow any occurrence of a + in the text mode to be rendered as if \raisebox{..}{+} was written instead. For example, in C you can define macros that perform literal string substitutions in the source code before compilation. The analogy is not complete, because C macros are not context-aware. — SU3, Oct 17 '20 at 23:49
as I said in my answer you could do that (same as ~ turns into \nobreakspace) but there are constructs that would break where + is used in arithmetic expressions. If you are feeling brave, define \~ as in my or egreg's answer then do \catcode\+=\active \def+{\relax\ifmmode\string+\else+\fi}` (TeX consists almost entirely of macro expansion in the sense of C macros, and nothing in the sense of C compiled functions) — David Carlisle, Oct 17 '20 at 23:51
I agree now that \+ seems a better option than redefining the + entirely. But thanks for the explanation. I may find a use for this later. — SU3, Oct 17 '20 at 23:59

score 8 · Accepted Answer · answered Oct 17 '20 at 23:14

I'm not sure that 0.25ex is the right choice: it actually makes the + sign to be slightly higher than a capital letter.

Using different fonts might also make the situation even worse. For instance, with Times you'd get

because here the + sign sits on the baseline. Can we make the raising independent of the font? Yes: a bit of algebra shows that we need to raise the symbol by half the sum of a capital letter, minus the height of + plus the height of +.

Using David's idea:

\newcommand{\+}{%
  \raisebox{\dimexpr(\fontcharht\font`X-\height+\depth)/2\relax}{+}%
}

Here's the output with Times

and with Computer Modern

Here's a visual proof of the statement about the height. The first + is with my definition, the second is raised 0.25ex. Just look at the top, because at the bottom TeX always uses the baseline.

score 7 · Answer 2 · answered Oct 17 '20 at 22:29

You could make + active and raise itself in text mode and not in math, but something would break, it is quite hard to catch all cases of \dimexpr \parindent + 5pt\relax and ensure you don't add a \raisebox mid-expression.

I would use a new command for it, \+ isn't defined by default so:

\documentclass{article}
\newcommand+{\raisebox{0.25ex}{+}}
\begin{document}
NNLL+NNLO
NNLL+NNLO
\end{document}

loved.by.Jesus · Answer 3 · 2021-11-12T12:00:18.653

Here my solution for a + sign between text letters (inspired in this answer). It has following features:

I offer both a solution for capital (\Plus) and lower case (\plus) letters. For the lower case, I recommend to reduce the size.
I use a different syntax.

    \documentclass{article}
    \usepackage{calc}
    \usepackage{graphicx}
%Plus for lower case
\newlength{\heightofx}
%Plus size is reduced to 60% (0.6)
%and set at the mid height of 'x'
\newcommand{\plus}{\settoheight{\heightofx}{x}%
\raisebox{0.5\heightofx-(0.5\totalheight-\depth)}%
{\scalebox{0.6}{+}}} 

%Plus for captitals
\newlength{\heightofX}
%Plus is set at the mid height of 'X'
\newcommand{\Plus}{\settoheight{\heightofX}{X}%
\raisebox{0.5\heightofX-(0.5\totalheight-\depth)}{+}} 

\begin{document}

\begin{tabular}{cc}
Adapted &amp; Raw \\
\hline
 \\[-0.5em]
LOVE\Plus GRACE &amp; LOVE+GRACE\\
love\plus grace &amp; love+grace
\end{tabular}

\end{document}

Always raise plus sign in text

3 Answers3