Fixed small but in ChainProcessor

src/main/scala/leon/purescala/PrettyPrinter.scala

src/main/scala/leon/purescala/Trees.scala

src/main/scala/leon/purescala/TypeTrees.scala

src/main/scala/leon/termination/ChainBuilder.scala

src/main/scala/leon/termination/ChainComparator.scala

src/main/scala/leon/termination/ChainProcessor.scala

src/main/scala/leon/termination/LoopProcessor.scala

src/main/scala/leon/termination/Processor.scala

src/main/scala/leon/termination/RecursionProcessor.scala

src/main/scala/leon/termination/RelationBuilder.scala

src/main/scala/leon/termination/RelationComparator.scala

src/main/scala/leon/termination/RelationProcessor.scala

src/main/scala/leon/termination/StructuralSize.scala