Content model for the <chem-struct> element, which holds a chemical expression, reaction, equation, etc., that is set apart within the text
<!ENTITY % chem-struct-model "(#PCDATA | %access.class; | %break.class; | %emphasis.class; | %label.class; | %list.class; | %math.class; | %simple-display.class; | %simple-link.class; | %subsup.class;)*" >
display.ent