<!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook V3.1//EN"> <para> Einstien's most famous equation, <inlineequation> <inlinemediaobject> <imageobject> <imagedata fileref="figures/emc2.gif"> </imageobject> <textobject> <phrase>E=mc<superscript>2</superscript></phrase> </textobject> </inlinemediaobject> </inlineequation>, expresses the relationship between matter and energy. </para>