31.1 Overview
 31.2 PDF Document
 31.3 PDF Objects
  31.3.1 Arrays
 31.4 PDF Operator Processors
  31.4.1 Run processor
  31.4.2 Filter processor
  31.4.3 Buffer processor
  31.4.4 Output processor
 31.5 Copying objects between PDF documents
  31.5.1 The problem
  31.5.2 Grafting objects
  31.5.3 A further problem
  31.5.4 Graft maps