--- a/progs/Application0.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,24 +0,0 @@
-package controllers
-
-import play.api._
-import play.api.mvc._
-
-// hello world program: 
-// just answer the GET request with a string
-
-object Application extends Controller {
-
-  // answering a GET request
-  def index = Action {
-    Ok(views.html.index("222Your new application is ready."))
-    //Ok("Hello World")
-  }  
-  
-}
-
-/*
- * HTML can be returned using
- *
- * Ok("<H1>Hello world!</H1>").as(HTML)
- *
- */ 

--- a/progs/Application1.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,39 +0,0 @@
-package controllers
-
-import play.api._
-import play.api.mvc._
-import play.api.data._
-import play.api.data.Forms._
-
-/*
- * Answers a GET-request by sending a simple login form.
- *
- * Processes the POST-data by just printing the results.
- *
- */
-
-object Application extends Controller {
-
-  // GET request -> login form
-  val index = Action { request =>
-    
-    val form = """
-               <form method="post"> 
-               Login: <input type="text" name="login"><br>
-               Password: <input type="password" name="password"><br>
-               <input type="submit"></form>"""
-
-    Ok(form).as(HTML)
-  }  
-
-  
-  // POST data: processing the login data
-  val receive = Action { request =>
-    
-    val form_data = Form(tuple ("login" -> text, "password" -> text))
-    val (login, password) = form_data.bindFromRequest()(request).get 
-    
-    Ok(s"Received login: $login and password: $password")
-  }
-  
-}

--- a/progs/Application2.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,43 +0,0 @@
-package controllers
-
-import play.api.mvc._
-
-/*
- * Application sets a cookie in plain ASCII on the
- * client's browser recording the number of visits
- * of a page.
- */
-
-object Application extends Controller {
-
-  //no or invalid cookie results in the counter being 0
-  def gt_cookie(c: Cookie) : Int = c.value match {
-    case s if (s.forall(_.isDigit)) => s.toInt 
-    case _ => 0
-  }
-
-  def mk_cookie(i: Int) : Cookie = {
-    Cookie("visits", i.toString)
-  }
-  
-  // GET request: read cookie data first
-  def index = Action { request =>
- 
-    //reads the cookie and extracts the visits counter   
-    val visits_cookie = request.cookies.get("visits")
-    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
-
-    //printing a message according to value of visits counter
-    val msg = 
-      if (visits >= 10)
-        s"You are a valued customer who has visited this site $visits times."               
-      else s"You have visited this site $visits times."
-    
-    //send message with new cookie
-    Ok(msg).withCookies(mk_cookie(visits + 1))
-  }
-}
-
-
-
-

--- a/progs/Application3.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,50 +0,0 @@
-package controllers
-
-import play.api.mvc._
-import java.security.MessageDigest
-
-/*
- * Application sets a cookie in plain ASCII on the
- * clients browser recording the visits of a page.
- *
- * The cookie data is hashed and stored in the format:
- *
- * visits_counter/hashed_value 
- */
-
-object Application extends Controller {
-
-  //hash functions: SHA-1, SHA-256, etc
-  def mk_hash(s: String) : String = {
-    val hash_fun = MessageDigest.getInstance("SHA-1")
-    hash_fun.digest(s.getBytes).map{ "%02x".format(_) }.mkString
-  }
-
-  //extracting from the string .../... the visits
-  //value and hash
-  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
-    case Array(s, h) if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
-    case _ => 0
-  }
-
-  def mk_cookie(i: Int) : Cookie = {
-    val hash = mk_hash(i.toString)
-    Cookie("visits", s"$i/$hash")
-  }
-   
-  def index = Action { request =>
-    val visits_cookie = request.cookies.get("visits")
-    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
-
-    val msg = 
-      if (visits >= 10)
-        s"You are a valued customer who has visited this site $visits times."               
-      else s"You have visited this site $visits times."
-    
-    Ok(msg).withCookies(mk_cookie(visits + 1))
-  }     
-}
-
-
-
-

--- a/progs/Application4.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,52 +0,0 @@
-package controllers
-
-import play.api.mvc._
-import java.security.MessageDigest
-
-/*
- * Application sets a cookie in plain ASCII on the
- * clients browser recording the visits of a page.
- *
- * The cookie data is hashed and salted with a
- * secret key.
- */
-
-
-object Application extends Controller {
-
-  //secret key for salting 
-  val salt = "my secret key"
-
-  //SHA-1 + salt
-  def mk_hash(s: String) : String = {
-    val hash_fun = MessageDigest.getInstance("SHA-1")
-    hash_fun.digest((s + salt).getBytes).map{ "%02x".format(_) }.mkString
-  }
-
-  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
-    case Array(s, h) if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
-    case _ => 0
-  }
-
-  def mk_cookie(i: Int) : Cookie = {
-    val hash = mk_hash(i.toString)
-    Cookie("visits", s"$i/$hash")
-  }
-   
-  def index = Action { request =>
-
-    val visits_cookie = request.cookies.get("visits")
-    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
-
-    val msg = 
-      if (visits >= 10)
-        s"You are a valued customer who has visited this site $visits times."               
-      else s"You have visited this site $visits times."
-    
-    Ok(msg).withCookies(mk_cookie(visits + 1))
-  }     
-}
-
-
-
-

--- a/progs/app0.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,13 +0,0 @@
-package controllers
-import play.api.mvc._
-
-object Application extends Controller {
-
-  // answering a GET request
-  val index = Action { request =>
-    Ok("Hello world!")
-  }  
-}
-
-
-

--- a/progs/app1.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,26 +0,0 @@
-object Application extends Controller {
-
-  // GET request -> present login form
-  val index = Action { request =>
-    
-    val form = 
-       """<form method="post"> 
-          Login: <input type="text" name="login"><br>
-          Password: <input type="password" name="password"><br>
-          <input type="submit"></form>"""
-
-    Ok(form).as(HTML)
-  }  
-
-  // POST data: processing the login data
-  val receive = Action { request =>
-    
-    val form_data = Form(tuple ("login" -> text, "password" -> text))
-    def (login, passwd) = form_data.bindFromRequest()(request).get
-    
-    Ok(s"Received login: $login and password: $passwd")
-  }
-}
-
-
-

--- a/progs/app2.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,30 +0,0 @@
-object Application extends Controller {
-
-  def gt_cookie(c: Cookie) : Int = c.value match {
-    case s if (s.forall(_.isDigit)) => s.toInt 
-    case _ => 0
-  }
-
-  def mk_cookie(i: Int) : Cookie = Cookie("visits", i.toString)
-  
-  // GET request: read cookie data first
-  def index = Action { request =>
- 
-    //reads the cookie and extracts the visits counter   
-    val visits_cookie = request.cookies.get("visits")
-    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
-
-    //printing a message according to value of visits counter
-    val msg = 
-      if (visits >= 10)
-        s"You are a valued customer who has visited this site $visits times."               
-      else s"You have visited this site $visits times."
-    
-    //send message with new cookie
-    Ok(msg).withCookies(mk_cookie(visits + 1))
-  }
-}
-
-
-
-

--- a/progs/app3.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,25 +0,0 @@
-object Application extends Controller {
-
-  //SHA-1, SHA-256
-  def mk_hash(s: String) : String = {
-    val hash_fun = MessageDigest.getInstance("SHA-1")
-    hash_fun.digest(s.getBytes).map{ "%02x".format(_) }.mkString
-  }
-
-  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
-    case Array(s, h) 
-      if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
-    case _ => 0
-  }
-
-  def mk_cookie(i: Int) : Cookie = {
-    val hash = mk_hash(i.toString)
-    Cookie("visits", s"$i/$hash")
-  }
-   
-  def index = Action { request => ... }     
-}
-
-
-
-

--- a/progs/app4.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,27 +0,0 @@
-object Application extends Controller {
-
-  val salt = "my secret key"
-
-  //SHA-1 + salt
-  def mk_hash(s: String) : String = {
-    val hash_fun = MessageDigest.getInstance("SHA-1")
-    hash_fun.digest((s + salt).getBytes).map{ "%02x".format(_) }.mkString
-  }
-
-  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
-    case Array(s, h) 
-      if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
-    case _ => 0
-  }
-
-  def mk_cookie(i: Int) : Cookie = {
-    val hash = mk_hash(i.toString)
-    Cookie("visits", s"$i/$hash")
-  }
-   
-  def index = Action { request => ... }
-}
-
-
-
-

--- a/progs/prove.scala	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,179 +0,0 @@
-import scala.language.implicitConversions
-import scala.language.reflectiveCalls
-import scala.util._
-
-abstract class Term 
-case class Var(s: String) extends Term 
-case class Const(s: String) extends Term 
-case class Fun(s: String, ts: List[Term]) extends Term
-
-abstract class Form
-case object True extends Form
-case object False extends Form
-case class Pred(s: String, ts: List[Term]) extends Form
-case class Imp(f1: Form, f2: Form) extends Form
-case class Says(p: String, f: Form) extends Form 
-case class And(f1: Form, f2: Form) extends Form 
-case class Or(f1: Form, f2: Form) extends Form 
-case class Sends(p: String, q: String, f: Form) extends Form
-case class Enc(f1: Form, f2: Form) extends Form
-
-case class Judgement(gamma: Set[Form], f: Form) {
-  def lhs = gamma
-  def rhs = f
-}
-
-// some syntactic sugar
-implicit def FormOps(f1: Form) = new {
-  def -> (f2: Form) = Imp(f1, f2)
-}
-implicit def StringOps(p: String) = new {
-  def says (f: Form) = Says(p, f)
-}
-implicit def SetFormOps(gamma: Set[Form]) = new {
-  def |- (f: Form) : Judgement = Judgement(gamma, f)
-}
-
-val Admin = "Admin"
-val Bob = "Bob"
-val Del = Pred("del_file", Nil)
-
-val Gamma: Set[Form] = 
-  Set( (Admin says Del) -> Del,
-       Admin says ((Bob says Del) -> Del),
-       Bob says Del )
-
-val goal = Gamma |- Del // request: provable or not?
-
-def partitions[A](s: Set[A]): Set[(A, Set[A])]  = 
-  s.map (e => (e, s - e))
-
-
-def prove(j: Judgement, sc: () => Unit) : Unit = {
-  if (j.lhs.contains(j.rhs))  sc ()   // Axiom rule 
-  else { 
-    prove1(j, sc);
-    for ((f, lhs_rest) <- partitions(j.lhs)) prove2(f, lhs_rest, j.rhs, sc)
-  }
-}
-
-def prove1(j: Judgement, sc: () => Unit) : Unit = 
-  j.rhs match {
-    case True => sc ()
-    case False => ()
-    case Imp(f1, f2) => prove(j.lhs + f1 |- f2, sc) 
-    case Says(p, Enc(f1, f2)) => 
-      prove(j.lhs |- Says(p, f1), 
-            () => prove(j.lhs |- Says(p, f2), sc))
-    case Says(p, f1) => prove(j.lhs |- f1, sc) 
-    case Or(f1, f2) => 
-      { prove(j.lhs |- f1, sc);
-        prove(j.lhs |- f2, sc) }
-    case And(f1, f2) => 
-      prove(j.lhs |- f1, 
-            () => prove(j.lhs |- f2, sc))
-    case Sends(p, q, f) => prove(j.lhs + (p says f) |- (q says f), sc)
-    case _ => ()
-  }
-
-def prove2(f: Form, lhs_rest: Set[Form], rhs: Form, sc: () => Unit) : Unit = 
-  f match {
-    case True => prove(lhs_rest |- rhs, sc)
-    case False => sc ()
-    case And(f1, f2) =>
-      prove(lhs_rest + f1 + f2 |- rhs, sc)
-    case Imp(f1, f2) => 
-      prove(lhs_rest |- f1, 
-            () => prove(lhs_rest + f2 |- rhs, sc))
-    case Sends(p, q, f) => 
-      prove(lhs_rest |- (p says f), 
-            () => prove(lhs_rest + (q says f) |- rhs, sc))
-    case Enc(f1, f2) => 
-      prove(lhs_rest |- f1, 
-            () => prove(lhs_rest + f2 |- rhs, sc))
-    case Or(f1, f2) => 
-      prove(lhs_rest + f1 |- rhs, 
-            () => prove(lhs_rest + f2 |- rhs, sc))
-    case Says(p, Enc(f1, f2)) => 
-      prove(lhs_rest |- Says(p, f2), 
-            () => prove(lhs_rest + Says(p, f1) |- rhs, sc))
-    case Says(p, Imp(f1, f2)) => 
-      prove(lhs_rest |- Says(p, f1), 
-            () => prove(lhs_rest + Says(p, f2) |- rhs, sc))
-     
-    case _ => ()
-  }
-
-// function that calls prove and returns immediately once a proof is found
-def run (j : Judgement) : Unit = {
-  def sc () = { println ("Yes!"); throw new Exception }
-  Try(prove(j, sc)) getOrElse ()
-} 
-
-run (goal)
-
-run (Set[Form]() |- False -> Del)
-run (Set[Form]() |- True -> Del)
-run (Set[Form]() |- Del -> True)
-run (Set[Form]() |- Del -> Del)
-run (Set[Form]() |- Del -> Or(False, Del))
-
-
-val Gamma1 : Set[Form] = 
-  Set( Admin says ((Bob says Del) -> Del),
-       Bob says Del )
-
-val goal1 = Gamma1 |- Del // not provable
-run (goal1)
-
-
-val f1 = "P" says Pred("F1", Nil)
-val f2 = "Q" says Pred("F2", Nil)
-run (Set[Form](And(f1, f2)) |- And(f2, f1))
-
-
-val Chr = "Christian"
-val HoD = "Peter"
-val Email = Pred("may_obtain_email", List(Const(Chr)))
-val AtLib = Pred("is_at_library", List(Const(Chr)))
-val Chr_Staff = Pred("is_staff", List(Const(Chr)))
-
-val Policy_HoD = (HoD says Chr_Staff) -> Chr_Staff
-val Policy_Lib = And(Chr_Staff, AtLib) -> Email
-val HoD_says = HoD says Chr_Staff
-
-run (Set[Form](AtLib, Policy_HoD, Policy_Lib) |- Email)
-
-println("Server Example")
-
-def Connect(p: String, q: String) : Form =
-  Pred("Connect", List(Var(p), Var(q)))
-
-
-val A = "A"
-val B = "B"
-val S = "S"
-val CAB = Connect(A, B)
-val Msg = Pred("Msg", Nil)
-val KAS = Pred("Kas", Nil)
-val KBS = Pred("Kbs", Nil)
-val KAB = Pred("Kab", Nil)
-
-val Gamma_big : Set[Form] = 
-  Set( A says CAB,
-       Sends(A, S, CAB), 
-       S says (CAB -> Enc(KAB, KAS)),
-       S says (CAB -> Enc(Enc(KAB, KBS), KAS)),
-       Sends(S, A, Enc(KAB, KAS)),
-       Sends(S, A, Enc(Enc(KAB, KBS), KAS)),
-       Sends(A, B, Enc(KAB, KBS)),
-       Sends(A, B, Enc(Msg, KAB)),
-       A says KAS,
-       B says KBS,
-       S says KAS,
-       A says (Enc(Msg, KAB))
-     )
-
-run (Gamma_big |- (B says Msg))
-
-

--- a/progs/routes	Sat Oct 04 00:36:51 2014 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,10 +0,0 @@
-# Application1 needs entries for both GET and POST 
-#
-# all other applications only need an entry for GET
-
-# Home page
-GET     /                           controllers.Application.index
-#POST    /                           controllers.Application.receive
-
-# Map static resources from the /public folder to the /assets URL path
-GET     /assets/*file               controllers.Assets.at(path="/public", file)
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/Application0.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,24 @@
+package controllers
+
+import play.api._
+import play.api.mvc._
+
+// hello world program: 
+// just answer the GET request with a string
+
+object Application extends Controller {
+
+  // answering a GET request
+  def index = Action {
+    Ok(views.html.index("222Your new application is ready."))
+    //Ok("Hello World")
+  }  
+  
+}
+
+/*
+ * HTML can be returned using
+ *
+ * Ok("<H1>Hello world!</H1>").as(HTML)
+ *
+ */ 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/Application1.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,39 @@
+package controllers
+
+import play.api._
+import play.api.mvc._
+import play.api.data._
+import play.api.data.Forms._
+
+/*
+ * Answers a GET-request by sending a simple login form.
+ *
+ * Processes the POST-data by just printing the results.
+ *
+ */
+
+object Application extends Controller {
+
+  // GET request -> login form
+  val index = Action { request =>
+    
+    val form = """
+               <form method="post"> 
+               Login: <input type="text" name="login"><br>
+               Password: <input type="password" name="password"><br>
+               <input type="submit"></form>"""
+
+    Ok(form).as(HTML)
+  }  
+
+  
+  // POST data: processing the login data
+  val receive = Action { request =>
+    
+    val form_data = Form(tuple ("login" -> text, "password" -> text))
+    val (login, password) = form_data.bindFromRequest()(request).get 
+    
+    Ok(s"Received login: $login and password: $password")
+  }
+  
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/Application2.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,43 @@
+package controllers
+
+import play.api.mvc._
+
+/*
+ * Application sets a cookie in plain ASCII on the
+ * client's browser recording the number of visits
+ * of a page.
+ */
+
+object Application extends Controller {
+
+  //no or invalid cookie results in the counter being 0
+  def gt_cookie(c: Cookie) : Int = c.value match {
+    case s if (s.forall(_.isDigit)) => s.toInt 
+    case _ => 0
+  }
+
+  def mk_cookie(i: Int) : Cookie = {
+    Cookie("visits", i.toString)
+  }
+  
+  // GET request: read cookie data first
+  def index = Action { request =>
+ 
+    //reads the cookie and extracts the visits counter   
+    val visits_cookie = request.cookies.get("visits")
+    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
+
+    //printing a message according to value of visits counter
+    val msg = 
+      if (visits >= 10)
+        s"You are a valued customer who has visited this site $visits times."               
+      else s"You have visited this site $visits times."
+    
+    //send message with new cookie
+    Ok(msg).withCookies(mk_cookie(visits + 1))
+  }
+}
+
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/Application3.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,50 @@
+package controllers
+
+import play.api.mvc._
+import java.security.MessageDigest
+
+/*
+ * Application sets a cookie in plain ASCII on the
+ * clients browser recording the visits of a page.
+ *
+ * The cookie data is hashed and stored in the format:
+ *
+ * visits_counter/hashed_value 
+ */
+
+object Application extends Controller {
+
+  //hash functions: SHA-1, SHA-256, etc
+  def mk_hash(s: String) : String = {
+    val hash_fun = MessageDigest.getInstance("SHA-1")
+    hash_fun.digest(s.getBytes).map{ "%02x".format(_) }.mkString
+  }
+
+  //extracting from the string .../... the visits
+  //value and hash
+  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
+    case Array(s, h) if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
+    case _ => 0
+  }
+
+  def mk_cookie(i: Int) : Cookie = {
+    val hash = mk_hash(i.toString)
+    Cookie("visits", s"$i/$hash")
+  }
+   
+  def index = Action { request =>
+    val visits_cookie = request.cookies.get("visits")
+    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
+
+    val msg = 
+      if (visits >= 10)
+        s"You are a valued customer who has visited this site $visits times."               
+      else s"You have visited this site $visits times."
+    
+    Ok(msg).withCookies(mk_cookie(visits + 1))
+  }     
+}
+
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/Application4.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,52 @@
+package controllers
+
+import play.api.mvc._
+import java.security.MessageDigest
+
+/*
+ * Application sets a cookie in plain ASCII on the
+ * clients browser recording the visits of a page.
+ *
+ * The cookie data is hashed and salted with a
+ * secret key.
+ */
+
+
+object Application extends Controller {
+
+  //secret key for salting 
+  val salt = "my secret key"
+
+  //SHA-1 + salt
+  def mk_hash(s: String) : String = {
+    val hash_fun = MessageDigest.getInstance("SHA-1")
+    hash_fun.digest((s + salt).getBytes).map{ "%02x".format(_) }.mkString
+  }
+
+  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
+    case Array(s, h) if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
+    case _ => 0
+  }
+
+  def mk_cookie(i: Int) : Cookie = {
+    val hash = mk_hash(i.toString)
+    Cookie("visits", s"$i/$hash")
+  }
+   
+  def index = Action { request =>
+
+    val visits_cookie = request.cookies.get("visits")
+    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
+
+    val msg = 
+      if (visits >= 10)
+        s"You are a valued customer who has visited this site $visits times."               
+      else s"You have visited this site $visits times."
+    
+    Ok(msg).withCookies(mk_cookie(visits + 1))
+  }     
+}
+
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/app0.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,13 @@
+package controllers
+import play.api.mvc._
+
+object Application extends Controller {
+
+  // answering a GET request
+  val index = Action { request =>
+    Ok("Hello world!")
+  }  
+}
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/app1.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,26 @@
+object Application extends Controller {
+
+  // GET request -> present login form
+  val index = Action { request =>
+    
+    val form = 
+       """<form method="post"> 
+          Login: <input type="text" name="login"><br>
+          Password: <input type="password" name="password"><br>
+          <input type="submit"></form>"""
+
+    Ok(form).as(HTML)
+  }  
+
+  // POST data: processing the login data
+  val receive = Action { request =>
+    
+    val form_data = Form(tuple ("login" -> text, "password" -> text))
+    def (login, passwd) = form_data.bindFromRequest()(request).get
+    
+    Ok(s"Received login: $login and password: $passwd")
+  }
+}
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/app2.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,30 @@
+object Application extends Controller {
+
+  def gt_cookie(c: Cookie) : Int = c.value match {
+    case s if (s.forall(_.isDigit)) => s.toInt 
+    case _ => 0
+  }
+
+  def mk_cookie(i: Int) : Cookie = Cookie("visits", i.toString)
+  
+  // GET request: read cookie data first
+  def index = Action { request =>
+ 
+    //reads the cookie and extracts the visits counter   
+    val visits_cookie = request.cookies.get("visits")
+    val visits = visits_cookie.map(gt_cookie).getOrElse(0)
+
+    //printing a message according to value of visits counter
+    val msg = 
+      if (visits >= 10)
+        s"You are a valued customer who has visited this site $visits times."               
+      else s"You have visited this site $visits times."
+    
+    //send message with new cookie
+    Ok(msg).withCookies(mk_cookie(visits + 1))
+  }
+}
+
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/app3.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,25 @@
+object Application extends Controller {
+
+  //SHA-1, SHA-256
+  def mk_hash(s: String) : String = {
+    val hash_fun = MessageDigest.getInstance("SHA-1")
+    hash_fun.digest(s.getBytes).map{ "%02x".format(_) }.mkString
+  }
+
+  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
+    case Array(s, h) 
+      if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
+    case _ => 0
+  }
+
+  def mk_cookie(i: Int) : Cookie = {
+    val hash = mk_hash(i.toString)
+    Cookie("visits", s"$i/$hash")
+  }
+   
+  def index = Action { request => ... }     
+}
+
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/app4.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,27 @@
+object Application extends Controller {
+
+  val salt = "my secret key"
+
+  //SHA-1 + salt
+  def mk_hash(s: String) : String = {
+    val hash_fun = MessageDigest.getInstance("SHA-1")
+    hash_fun.digest((s + salt).getBytes).map{ "%02x".format(_) }.mkString
+  }
+
+  def gt_cookie(c: Cookie) : Int = c.value.split("/") match {
+    case Array(s, h) 
+      if (s.forall(_.isDigit) && mk_hash(s) == h) => s.toInt 
+    case _ => 0
+  }
+
+  def mk_cookie(i: Int) : Cookie = {
+    val hash = mk_hash(i.toString)
+    Cookie("visits", s"$i/$hash")
+  }
+   
+  def index = Action { request => ... }
+}
+
+
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/prove.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,179 @@
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+import scala.util._
+
+abstract class Term 
+case class Var(s: String) extends Term 
+case class Const(s: String) extends Term 
+case class Fun(s: String, ts: List[Term]) extends Term
+
+abstract class Form
+case object True extends Form
+case object False extends Form
+case class Pred(s: String, ts: List[Term]) extends Form
+case class Imp(f1: Form, f2: Form) extends Form
+case class Says(p: String, f: Form) extends Form 
+case class And(f1: Form, f2: Form) extends Form 
+case class Or(f1: Form, f2: Form) extends Form 
+case class Sends(p: String, q: String, f: Form) extends Form
+case class Enc(f1: Form, f2: Form) extends Form
+
+case class Judgement(gamma: Set[Form], f: Form) {
+  def lhs = gamma
+  def rhs = f
+}
+
+// some syntactic sugar
+implicit def FormOps(f1: Form) = new {
+  def -> (f2: Form) = Imp(f1, f2)
+}
+implicit def StringOps(p: String) = new {
+  def says (f: Form) = Says(p, f)
+}
+implicit def SetFormOps(gamma: Set[Form]) = new {
+  def |- (f: Form) : Judgement = Judgement(gamma, f)
+}
+
+val Admin = "Admin"
+val Bob = "Bob"
+val Del = Pred("del_file", Nil)
+
+val Gamma: Set[Form] = 
+  Set( (Admin says Del) -> Del,
+       Admin says ((Bob says Del) -> Del),
+       Bob says Del )
+
+val goal = Gamma |- Del // request: provable or not?
+
+def partitions[A](s: Set[A]): Set[(A, Set[A])]  = 
+  s.map (e => (e, s - e))
+
+
+def prove(j: Judgement, sc: () => Unit) : Unit = {
+  if (j.lhs.contains(j.rhs))  sc ()   // Axiom rule 
+  else { 
+    prove1(j, sc);
+    for ((f, lhs_rest) <- partitions(j.lhs)) prove2(f, lhs_rest, j.rhs, sc)
+  }
+}
+
+def prove1(j: Judgement, sc: () => Unit) : Unit = 
+  j.rhs match {
+    case True => sc ()
+    case False => ()
+    case Imp(f1, f2) => prove(j.lhs + f1 |- f2, sc) 
+    case Says(p, Enc(f1, f2)) => 
+      prove(j.lhs |- Says(p, f1), 
+            () => prove(j.lhs |- Says(p, f2), sc))
+    case Says(p, f1) => prove(j.lhs |- f1, sc) 
+    case Or(f1, f2) => 
+      { prove(j.lhs |- f1, sc);
+        prove(j.lhs |- f2, sc) }
+    case And(f1, f2) => 
+      prove(j.lhs |- f1, 
+            () => prove(j.lhs |- f2, sc))
+    case Sends(p, q, f) => prove(j.lhs + (p says f) |- (q says f), sc)
+    case _ => ()
+  }
+
+def prove2(f: Form, lhs_rest: Set[Form], rhs: Form, sc: () => Unit) : Unit = 
+  f match {
+    case True => prove(lhs_rest |- rhs, sc)
+    case False => sc ()
+    case And(f1, f2) =>
+      prove(lhs_rest + f1 + f2 |- rhs, sc)
+    case Imp(f1, f2) => 
+      prove(lhs_rest |- f1, 
+            () => prove(lhs_rest + f2 |- rhs, sc))
+    case Sends(p, q, f) => 
+      prove(lhs_rest |- (p says f), 
+            () => prove(lhs_rest + (q says f) |- rhs, sc))
+    case Enc(f1, f2) => 
+      prove(lhs_rest |- f1, 
+            () => prove(lhs_rest + f2 |- rhs, sc))
+    case Or(f1, f2) => 
+      prove(lhs_rest + f1 |- rhs, 
+            () => prove(lhs_rest + f2 |- rhs, sc))
+    case Says(p, Enc(f1, f2)) => 
+      prove(lhs_rest |- Says(p, f2), 
+            () => prove(lhs_rest + Says(p, f1) |- rhs, sc))
+    case Says(p, Imp(f1, f2)) => 
+      prove(lhs_rest |- Says(p, f1), 
+            () => prove(lhs_rest + Says(p, f2) |- rhs, sc))
+     
+    case _ => ()
+  }
+
+// function that calls prove and returns immediately once a proof is found
+def run (j : Judgement) : Unit = {
+  def sc () = { println ("Yes!"); throw new Exception }
+  Try(prove(j, sc)) getOrElse ()
+} 
+
+run (goal)
+
+run (Set[Form]() |- False -> Del)
+run (Set[Form]() |- True -> Del)
+run (Set[Form]() |- Del -> True)
+run (Set[Form]() |- Del -> Del)
+run (Set[Form]() |- Del -> Or(False, Del))
+
+
+val Gamma1 : Set[Form] = 
+  Set( Admin says ((Bob says Del) -> Del),
+       Bob says Del )
+
+val goal1 = Gamma1 |- Del // not provable
+run (goal1)
+
+
+val f1 = "P" says Pred("F1", Nil)
+val f2 = "Q" says Pred("F2", Nil)
+run (Set[Form](And(f1, f2)) |- And(f2, f1))
+
+
+val Chr = "Christian"
+val HoD = "Peter"
+val Email = Pred("may_obtain_email", List(Const(Chr)))
+val AtLib = Pred("is_at_library", List(Const(Chr)))
+val Chr_Staff = Pred("is_staff", List(Const(Chr)))
+
+val Policy_HoD = (HoD says Chr_Staff) -> Chr_Staff
+val Policy_Lib = And(Chr_Staff, AtLib) -> Email
+val HoD_says = HoD says Chr_Staff
+
+run (Set[Form](AtLib, Policy_HoD, Policy_Lib) |- Email)
+
+println("Server Example")
+
+def Connect(p: String, q: String) : Form =
+  Pred("Connect", List(Var(p), Var(q)))
+
+
+val A = "A"
+val B = "B"
+val S = "S"
+val CAB = Connect(A, B)
+val Msg = Pred("Msg", Nil)
+val KAS = Pred("Kas", Nil)
+val KBS = Pred("Kbs", Nil)
+val KAB = Pred("Kab", Nil)
+
+val Gamma_big : Set[Form] = 
+  Set( A says CAB,
+       Sends(A, S, CAB), 
+       S says (CAB -> Enc(KAB, KAS)),
+       S says (CAB -> Enc(Enc(KAB, KBS), KAS)),
+       Sends(S, A, Enc(KAB, KAS)),
+       Sends(S, A, Enc(Enc(KAB, KBS), KAS)),
+       Sends(A, B, Enc(KAB, KBS)),
+       Sends(A, B, Enc(Msg, KAB)),
+       A says KAS,
+       B says KBS,
+       S says KAS,
+       A says (Enc(Msg, KAB))
+     )
+
+run (Gamma_big |- (B says Msg))
+
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/scala/random.scala	Sat Oct 04 12:46:04 2014 +0100
@@ -0,0 +1,18 @@
+
+val m = 16
+val a = 5
+val c = 1
+val X0 = 10
+
+def ran(n: Int, X: Int) : Set[Int] = n match {
+  case 0 => Set()
+  case n => {
+    val X_new = (a * X + c) % m
+    Set(X) ++ ran(n - 1, X_new) 
+  }
+}
+
+for (i <- 0 to 16) {
+  val l = ran(16, i)
+  println(l.size.toString + " " + l.toString)
+}