Lok Sabha Speaker Om Birla expressed grief over the demise of the former President and said, Pranab Mukherjee in his more than five decade long public life, served the nation with exemplary dedication. <br />''<br />''<span style="color: #222222;">He said, Mukherjee's experience in parliamentary and administrative matters was unmatched, a quality which manifested itself in his extraordinary work ethic.</span><br />