$${\mathtt{\,-\,}}{\mathtt{6}}{\mathtt{\,\times\,}}{{\mathtt{c}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}}{\mathtt{\,\times\,}}{{\mathtt{c}}}^{{\mathtt{2}}} = {\mathtt{3}}{\mathtt{\,\times\,}}{{\left(\underset{{\tiny{\text{Error: Unknown Identifier}}}}{{\mathtt{c}}}\right)}}^{{\mathtt{2}}}{\mathtt{\,-\,}}{\mathtt{6}}{\mathtt{\,\times\,}}{{\left(\underset{{\tiny{\text{Error: Unknown Identifier}}}}{{\mathtt{c}}}\right)}}^{{\mathtt{2}}}$$
.