| http://www.w3.org/ns/prov#value | - Examples of the dicarboxylic acid unit (a) include ##STR1## wherein X represents hydrogen, halogen, e.g. C1 or Br, an alkyl group, e.g. methyl, ethyl, propyl, isopropyl, butyl or t-butyl, an alkoxy group, e.g. methoxy, ethoxy, propoxy or buthoxy, or phenyl group, and k is 0 to 2, ##STR2## and the like.
|
