In a similar way, I also changed to show the error formula \[{\lim _{x \to - \infty }}f\left( x \right)\] to \[\mathop {\lim }\limits_{x \to - \infty } f\left( x \right)\]
by $texexp = str_replace('\mathop {','',$texexp);
You can comment this author mathtran edit this bugby $texexp = str_replace('\mathop {','',$texexp);
