Yes, though it would be `.semantic-container:not(:hover) > .exercise > .solution-controls { display: none; }`. Is the fact that `:not` isn't supported in IE8 -- which is apparently a browser that Aloha supports -- reason enough not to add more uses of `:not` into the code (on the assumption that one day we might actually want to support it too and then we'll have to revert to the above code)?