public IBlock GetCaretBrotherElement(bool before, Point caretPoint) { if (null != Molecule) { var block = Molecule.GetCaretBrotherElement(before, caretPoint); if (null != block) { return(block); } } if (null != Denominator) { var block = Denominator.GetCaretBrotherElement(before, caretPoint); if (null != block) { return(block); } } return(null); }