Fixed typo. Set threshold to 0.04 from 0.4

topology/isabel/task_description.txt

@@ -1,5 +1,5 @@
 1. Load the file "isabel/data/isabel.vti".
-2. Apply persistent simplification to the field "sf" with a persistence threshold of 0.4
+2. Apply persistent simplification to the field "sf" with a persistence threshold of 0.04
 3. Compute the merge tree of the simplified field.
 4. Save the nodes of the merge tree as "isabel/results/{agent_mode}/isabel_nodes.vtk" in legacy VTK format. 
 This file should have two point arrays. One should be called "CriticalType" and should store the type of critical point for each node.