| http://www.w3.org/ns/prov#value | - ##STR00030## where R.sub.1, R.sub.2 and Z.sub.1 to Z.sub.4 are independently chosen from hydrogen and organic moieties having about 1 60 carbon atoms, such as about 1 20, about 1 12, or about 1 6 carbon atoms. Suitable organic moieties can be
|
