Fix file names

src/main/scala/leon/invariant/datastructure/ExprStructure.scala

 package leon
 package invariant.util
 
-import purescala.Common._
-import purescala.Definitions._
 import purescala.Expressions._
 import purescala.ExprOps._
 import purescala.Extractors._
 import purescala.Types._
-import scala.collection.mutable.{ Set => MutableSet, Map => MutableMap }
 
 /**
  * A class that looks for structural equality of expressions

src/main/scala/leon/synthesis/programsets/UnionProgramset.scala → src/main/scala/leon/synthesis/programsets/UnionProgramSet.scala

@@ -3,12 +3,6 @@
 package leon
 package synthesis.programsets
 
-import leon.purescala
-import purescala.Expressions._
-import purescala.Extractors._
-import purescala.Constructors._
-import purescala.Types._
-
 object UnionProgramSet {
   def apply[T](sets: Seq[ProgramSet[T]]): UnionProgramSet[T] = {
     new UnionProgramSet(sets)