Migration to Isabelle 2020.

.ci/Jenkinsfile

@@ -3,7 +3,7 @@ pipeline {
     stages {
         stage('Build') {
             steps {
-                sh 'docker run -v $PWD/UPF_Firewall:/UPF_Firewall logicalhacking:isabelle2019 isabelle build -D /UPF_Firewall'
+                sh 'docker run -v $PWD/UPF_Firewall:/UPF_Firewall logicalhacking:isabelle2020 isabelle build -D /UPF_Firewall'
             }
         }
     }

UPF_Firewall/ROOT

@@ -3,6 +3,17 @@ chapter AFP
 session "UPF_Firewall-devel" (AFP) = UPF +
   description "Formal Network Models and Their Application to Firewall Policies"
   options [timeout = 600]
+  directories
+    "Examples"
+    "Examples/DMZ"
+    "Examples/NAT-FW"
+    "Examples/PersonalFirewall"
+    "Examples/Transformation"
+    "Examples/Voice_over_IP"
+    "FWNormalisation"
+    "NAT"
+    "PacketFilter"
+    "StatefulFW"
   theories
     "Examples/Examples"
   document_files