src/Baum/SetValidator.php
protected function isEachRootValid($roots) {
    $left = $right = 0;

    foreach($roots as $root) {
      $rootLeft   = $root->getLeft();
      $rootRight  = $root->getRight();

      if ( !($rootLeft > $left && $rootRight > $right) )
        return false;

      $left   = $rootLeft;
      $right  = $rootRight;
    }

    return true;
  }
protected function isEachRootValid($roots) {
    $left = $right = 0;

    foreach($roots as $root) {
      $rootLeft   = $root->getLeft();
      $rootRight  = $root->getRight();

      if ( !($rootLeft > $left && $rootRight > $right) )
        return false;

      $left   = $rootLeft;
      $right  = $rootRight;
    }

    return true;
  }
Check that each root node in the list supplied satisfies that its bounds
values (lft, rgt indexes) are less than the next.

@param   mixed   $roots
@return  boolean