VEC, BAR, DOT, DDOT, HAT and TILDE

These elements place an accent above the term enclosed by the element. VEC draws a right arrow above the term; BAR draws a line; DOT and DDOT draw a single and double dot respectively; HAT and TILDE draw the corresponding character above the term, for example:

                            ^
    <HAT>X</HAT>   giving   X
    
                                ~
    <TILDE>X</TILDE>   giving   X

Note: there are no attributes for these elements.