### A check sign crossed by a line?

The other day I saw someone posting a LaTeX question. He wanted $\check{x}$ and $\overline{x}$ to overlap, making a symbol just like a letter x with an accent check’ which is crossed by a line.

It’s my first time to mix up symbols in order to produce a new one, although previously I had seen many such examples. The first command popping up my mind was \kern. Hence I tried the following solution:

\newlength{\wdo} \newcommand{\checkoverline}[1]{\check{#1}% \settowidth{\wdo}{$\overline{#1}$} {\kern-\wdo}% \overline{\phantom{#1}}} 

Take the argument #1 to be the letter x for example. In line 2 I made \check{x}, and in line 4 I made \overline{x}. The x in \overline{x} is indeed invisible due to the usage of \phantom. Then the second (invisible) x is displaced to overlap with the first x by the 3rd line. What line 3 does is that it records the width of \overline{x} in \wdo, then moves \overline{x} by a displacement -\wdo. Now \check{x} and \overline{x} overlap!

I had tried to remove the command \phantom. Then both the x’s in \check{x} and \overline{x} are visible. When they overlap, in some printing devices the resultant x looks darker and bolder than usual. I ended up using the phantom to make the x look normal.

The following is finally what the new command \checkoverline` produces:

Honestly, I don’t know if this is what the guy posting the question wants—the symbols look so ugly..