Htydjtk

I would need to write a few letters above certain syllables in a normal text. I've found this great stackengine package, which seems to do the job.

documentclass{article}

usepackage{stackengine}

begin{document}

stackon{a}{w}stackon{b}{x} stackon{c}{y}stackon{d}{z}

end{document}

However, due to the different height of the letters, the vertical position of the stacked pieces of text is not even. How is it possible to balance somehow out this difference and create a kind of secondary line of the stacks above the main line?

The default stack type in stackengine are "Short" stacks that preserve the amount of empty vertical gap between letters in the stack. But there are also "Long" stacks that preserve the baselineskip. Therefore, merely invoke renewcommandstacktype{L}.

The default baselineskip is normalbaselineskip, but you can reset it with setstackgap{L}{<length>}. Or else you can pass an optional argument to the particular stack: stackon[<length>]{...}.

documentclass{article}

usepackage{stackengine}

begin{document}

renewcommandstacktype{L}

stackon{a}{w}stackon{b}{x} stackon{c}{y}stackon{d}{z}

end{document}

The package documentation, https://ctan.org/pkg/stackengine, lays this all out clearly.

A work-around, with vphantom and smash:

documentclass{article}

usepackage{stackengine, amsmath}



begin{document}



stackon{avphantom{b}}{w}stackon{b}{x} stackon{cvphantom{d}}{smash[b]{y}}stackon{d}{z}



end{document} 

Here's how I'd do it:

documentclass{article}



newcommand{aw}[2]{%

  leavevmodevbox{%

    offinterlineskip

    halign{%

      hfil##hfilcr

      vphantom{y}#2cr

      noalign{vskip0.4pt}

      vphantom{b}#1cr

    }%

  }%

}



begin{document}



aw{a}{w}aw{b}{x} aw{c}{y}aw{d}{z} aw{d}{q}



end{document}

A version where the letters at the top are smaller:

documentclass{article}



makeatletter

newcommand{aw}[2]{%

  leavevmodevbox{%

    check@mathfonts

    offinterlineskip

    halign{%

      hfil##hfilcr

      fontsize{ssf@size}{0}selectfont

      vphantom{y}#2cr

      noalign{vskip0.4pt}

      vphantom{b}#1cr

    }%

  }%

}

makeatother



begin{document}



aw{a}{w}aw{b}{x} aw{c}{y}aw{d}{z} aw{d}{q}



end{document}