anytrait.scala:3: error: field definition is not allowed in universal trait extending from class Any
  var x = 1
      ^
anytrait.scala:5: error: this statement is not allowed in universal trait extending from class Any
  { x += 1 }
      ^
anytrait.scala:9: error: field definition is not allowed in universal trait extending from class Any
  val y: T
      ^
three errors found