Created attachment 673 [details]
example of typical equation

1. i) select text element (e.g. Bz) ii) delete it iii) move to msup>base iv) ctrl+x to insert text and see what happen: <msub><mrow><mtext/><mtext/></mrow></msub>
2. Put the cursor before "|=+". Try to move right. Should be: "=|+". Actually: "=+|". Similarly it is difficult to navigate other operators. For example, Delta, or invisible times and apply function operators.