This is the first block, with a big left margin. At the end of this block is a left float which should be square. Text that follows this box should flow to the right of the float or go below it; no text should be on the left of the float. This is the square left float. This is the second block. It is sized so as to be just wide enough to slightly overlap the float. Text shouldn't be able to fit around the float without overflowing this box, so instead all the text should just move below the float.