Minor modifications in planning_angelic_search.ipynb and knowledge_FOIL.ipynb notebooks (#949)

* Minor modifications in planning_angelic_search.ipynb and knowledge_FOIL.ipynb notebooks.

Author: MariannaSpyrakou

knowledge_FOIL.ipynb

@@ -587,10 +587,10 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The algorithm produced almost the recursive rule: \n",
+    "The algorithm produced something close to the recursive rule: \n",
     " $$ Reach(x,y) \\Leftrightarrow [Conn(x,y)] \\: \\lor \\: [\\exists \\: z \\: \\: Reach(x,z) \\, \\land  \\, Reach(z,y)]$$\n",
     " \n",
-    "This is because the size of the example is small. "
+    "This happened because the size of the example is small. "
    ]
   }
  ],

planning.py

@@ -1144,6 +1144,7 @@ def simple_blocks_world_graphplan():
     return GraphPlan(simple_blocks_world()).execute()
 
 
+
 class HLA(Action):
     """
     Define Actions for the real-world (that may be refined further), and satisfy resource
@@ -1363,9 +1364,8 @@ def angelic_search(problem, hierarchy, initialPlan):
                 guaranteed = problem.intersects_goal(pes_reachable_set) 
                 if guaranteed and Problem.making_progress(plan, initialPlan):
                     final_state = guaranteed[0] # any element of guaranteed 
-                    #print('decompose')
                     return Problem.decompose(hierarchy, problem, plan, final_state, pes_reachable_set)
-                (hla, index) = Problem.find_hla(plan, hierarchy) # there should be at least one HLA/Angelic_HLA, otherwise plan would be primitive.
+                hla, index = Problem.find_hla(plan, hierarchy) # there should be at least one HLA/Angelic_HLA, otherwise plan would be primitive.
                 prefix = plan.action[:index]
                 suffix = plan.action[index+1:]
                 outcome = Problem(Problem.result(problem.init, prefix), problem.goals , problem.actions )
@@ -1442,8 +1442,8 @@ def find_hla(plan, hierarchy):
                 hla = plan.action[i] 
                 index = i
                 break
-        return (hla, index)
-	
+        return hla, index
+
     def making_progress(plan, initialPlan):
         """ 
         Prevents from infinite regression of refinements  

planning_angelic_search.ipynb

@@ -11,8 +11,7 @@
     "-  problem is of type Problem \n",
     "-  hierarchy is a dictionary consisting of all the actions. \n",
     "-  initialPlan is an approximate description(optimistic and pessimistic) of the agents choices for the implementation. <br>\n",
-    "   It is a nested list, containing sequence a of actions with their optimistic and pessimistic\n",
-    "   description "
+    "   initialPlan contains a sequence of HLA's with angelic semantics"
    ]
   },
   {