fh_sin = @sin

fh_sin =

  <a href="matlab:helpPopup function_handle" style="font-weight:bold">function_handle</a> with value:

    @sin


functions (fh_sin)

ans = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

    function: 'sin'
        type: 'simple'
        file: ''

which ('sin')
built-in (C:\Program Files\MATLAB\R2019b\toolbox\matlab\elfun\@double\sin)  % double method
sin (pi)

ans =

   1.2246e-16

fh_sin (pi)

ans =

   1.2246e-16


cd subdir
[Warning: Function sin has the same name as a MATLAB builtin. We suggest you rename the function to avoid a potential name conflict.] 
[> In <a href="matlab:matlab.internal.language.introspective.errorDocCallback('tstscript', 'D:\SVN\Octave\builtin-fh-tst\tstscript.m', 11)" style="font-weight:bold">tstscript</a> (<a href="matlab: opentoline('D:\SVN\Octave\builtin-fh-tst\tstscript.m',11,0)">line 11</a>)] 

functions (fh_sin)

ans = 

  <a href="matlab:helpPopup struct" style="font-weight:bold">struct</a> with fields:

    function: 'sin'
        type: 'simple'
        file: ''

which ('sin')
D:\SVN\Octave\builtin-fh-tst\subdir\sin.m
sin (pi)

ans =

   1.2246e-16

fh_sin (pi)

ans =

   1.2246e-16


diary off