diff --git a/src/main/scala/leon/synthesis/disambiguation/QuestionBuilder.scala b/src/main/scala/leon/synthesis/disambiguation/QuestionBuilder.scala
index 7b0de3e68d992de2c5f5d3fc7d37568b77f325a1..e356d40bb5db668e1487792231d2b6b9dd6bd2c5 100644
--- a/src/main/scala/leon/synthesis/disambiguation/QuestionBuilder.scala
+++ b/src/main/scala/leon/synthesis/disambiguation/QuestionBuilder.scala
@@ -89,8 +89,8 @@ class QuestionBuilder[T <: Expr](input: Seq[Identifier], solutions: Stream[Solut
   private var _argTypes = input.map(_.getType)
   private var _questionSorMethod: QuestionSortingType = QuestionSortingType.IncreasingInputSize
   private var _alternativeSortMethod: AlternativeSortingType[T] = AlternativeSortingType.BalancedParenthesisIsBetter[T]() && AlternativeSortingType.ShorterIsBetter[T]() 
-  private var solutionsToTake = 15
-  private var expressionsToTake = 15
+  private var solutionsToTake = 30
+  private var expressionsToTake = 30
   private var keepEmptyAlternativeQuestions: T => Boolean = Set()
 
   /** Sets the way to sort questions. See [[QuestionSortingType]] */
diff --git a/testcases/stringrender/DoubleListRender.scala b/testcases/stringrender/DoubleListRender.scala
index 284760380abde82b5d9f317e3a390a5353c283a3..bd0dba714601685ae9c3ed22d199ff8c6a825daf 100644
--- a/testcases/stringrender/DoubleListRender.scala
+++ b/testcases/stringrender/DoubleListRender.scala
@@ -48,6 +48,16 @@ object DoubleListRender {
         "[([()])]"
       case B(BB(N(), BB(N(), BB(N(), NN()))), N()) =>
         "[([], [], [])]"
+      case B(NN(), B(BB(N(), NN()), B(NN(), N()))) =>
+        "[(), ([]), ()]"
+      case B(BB(B(NN(), N()), BB(N(), NN())), N()) =>
+        "[([()], [])]"
+      case B(BB(B(BB(N(), NN()), N()), NN()), N()) =>
+        "[([([])])]"
+      case B(BB(B(NN(), B(NN(), N())), NN()), N()) =>
+        "[([(), ()])]"
+      case B(BB(N(), BB(B(NN(), N()), NN())), N()) =>
+        "[([], [()])]"
     }
   }
 }
\ No newline at end of file