10 files changed, 11 insertions, 9 deletions
diff --git a/prolog/problems/trees/common.py b/prolog/problems/trees/common.py
index a519878..d9ebca1 100644
--- a/prolog/problems/trees/common.py
+++ b/prolog/problems/trees/common.py
@@ -1,2 +1,4 @@
 id = 6
 number = 5
+
+allowed_groups = ['lists']
diff --git a/prolog/problems/trees/deletebt_3/common.py b/prolog/problems/trees/deletebt_3/common.py
index 98ad95f..52f9e3f 100644
--- a/prolog/problems/trees/deletebt_3/common.py
+++ b/prolog/problems/trees/deletebt_3/common.py
@@ -2,7 +2,7 @@
 
 id = 137
 number = 47
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/depthbt_2/common.py b/prolog/problems/trees/depthbt_2/common.py
index 85dfa27..4542419 100644
--- a/prolog/problems/trees/depthbt_2/common.py
+++ b/prolog/problems/trees/depthbt_2/common.py
@@ -2,7 +2,7 @@
 
 id = 140
 number = 45
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/insertbt_3/common.py b/prolog/problems/trees/insertbt_3/common.py
index f8ef004..eb1ea94 100644
--- a/prolog/problems/trees/insertbt_3/common.py
+++ b/prolog/problems/trees/insertbt_3/common.py
@@ -2,7 +2,7 @@
 
 id = 138
 number = 48
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/maxt_2/common.py b/prolog/problems/trees/maxt_2/common.py
index 280cb25..b1cdb39 100644
--- a/prolog/problems/trees/maxt_2/common.py
+++ b/prolog/problems/trees/maxt_2/common.py
@@ -2,7 +2,7 @@
 
 id = 143
 number = 50
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/memberbt_2/common.py b/prolog/problems/trees/memberbt_2/common.py
index f5e5435..6df89e3 100644
--- a/prolog/problems/trees/memberbt_2/common.py
+++ b/prolog/problems/trees/memberbt_2/common.py
@@ -2,7 +2,7 @@
 
 id = 135
 number = 42
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/membert_2/common.py b/prolog/problems/trees/membert_2/common.py
index c91371e..7d8f207 100644
--- a/prolog/problems/trees/membert_2/common.py
+++ b/prolog/problems/trees/membert_2/common.py
@@ -2,7 +2,7 @@
 
 id = 142
 number = 49
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/mirrorbt_2/common.py b/prolog/problems/trees/mirrorbt_2/common.py
index cc271cc..1ee0a9c 100644
--- a/prolog/problems/trees/mirrorbt_2/common.py
+++ b/prolog/problems/trees/mirrorbt_2/common.py
@@ -2,7 +2,7 @@
 
 id = 136
 number = 43
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/numberbt_2/common.py b/prolog/problems/trees/numberbt_2/common.py
index 7df71d8..e75075e 100644
--- a/prolog/problems/trees/numberbt_2/common.py
+++ b/prolog/problems/trees/numberbt_2/common.py
@@ -2,7 +2,7 @@
 
 id = 139
 number = 44
-visible = True
+visible = False
 facts = None
 
 solution = '''\
diff --git a/prolog/problems/trees/tolistbt_2/common.py b/prolog/problems/trees/tolistbt_2/common.py
index e6c8ffd..3c14c4e 100644
--- a/prolog/problems/trees/tolistbt_2/common.py
+++ b/prolog/problems/trees/tolistbt_2/common.py
@@ -2,7 +2,7 @@
 
 id = 141
 number = 46
-visible = True
+visible = False
 facts = None
 
 solution = '''\