Xjyuk

I am trying to write the following line as can be seen below

documentclass[border=1mm]standalone
usepackagegraphicx
begindocument
Huge $cup cap raisebox0.30 exscalebox1[0.62]$mid$$ 
enddocument

Which results in

Is there an easier or better way to make sure the vertical line mid
is scaled correctly to cup and cap? In particular

• They should have the same baseline, height and width.

My solution feels very hackish and not quite right.

stretchrel from the scalerel package allows you to do such things.

documentclass[border=1mm]standalone
usepackagescalerel
begindocument
Huge $cup cap stretchrel*midcap$ 
enddocument

For Computer Modern, use pict2e:

documentclassarticle
usepackagepict2e
usepackagecolor % for the comparison

makeatletter
newcommandcbarmathbinmathpalettec@barrelax
newcommandc@bar[2]%
 begingroup
 sboxz@$#1cup$%
 setlengthunitlengthdimexprhtz@+dpz@%
 mkern1mu
 raisebox-dpz@%
 beginpicture(0,1)
 roundcap
 c@bar@thickness#1%
 Line(0,0)(0,1.03)
 endpicture%
 %
 mkern1mu
 endgroup

newcommandc@bar@thickness[1]%
 linethickness%
 ifx#1displaystyle 1fontdimen8textfontelse
 ifx#1textstyle 1fontdimen8textfontelse
 ifx#1scriptstyle 0.85fontdimen8scriptfontelse
 0.75fontdimen8scriptscriptfontfififi 3
 %

makeatother

begindocument

$cupcapcbar$

$scriptstylecupcapcbar$

$scriptscriptstylecupcapcbar$

$cupmkern-2.3mutextcolorredcbartextcolorredcupmkern-2.3mucbar$
$capmkern-2.3mutextcolorredcbartextcolorredcapmkern-2.3mucbar$

$scriptstylecupmkern-2.4mutextcolorredcbartextcolorredcupmkern-2.4mucbar$
$scriptstylecapmkern-2.4mutextcolorredcbartextcolorredcapmkern-2.4mucbar$

$scriptscriptstylecupmkern-2.8mutextcolorredcbartextcolorredcupmkern-2.8mucbar$
$scriptscriptstylecapmkern-2.8mutextcolorredcbartextcolorredcapmkern-2.8mucbar$

enddocument