isWellFormed()

bool MonomialIdeal::isWellFormed ( ) const

private

Definition at line 578 of file monideal.cpp.

{
  if (mi == nullptr) return true; // nothing else to check.
 
  Nmi_node* p = mi;
  while (p != nullptr)
    {
      // check the current node
      if (p->left == nullptr) throw exc::engine_error("left node link is null");
      if (p->right == nullptr) throw exc::engine_error("right node link is null");
      if (p->header == nullptr) throw exc::engine_error("header node link is null");
      if (p->tag == Nmi_node::node and p != mi and p->val.down == nullptr) throw exc::engine_error("down node link is null");
 
      // now go to the next node
      // if this is a leaf, go right.
      // if this is a header, go down (up), and one left
      // if this is an internal node, go down (to subtree).
      if (p->tag == Nmi_node::node and p->header != p)
        p = p->val.down;
      else if (p->tag == Nmi_node::node and p->header == p)
        {
          // this is a header node (head of the double linked list at this level)
          // Let's check all of the elements in the double ring at this level.
          for (Nmi_node* q = p->right; q != p; q = q->right)
            {
              if (p->var != q->var) throw exc::engine_error("variable index is not consistent");
              if (q->left->right != q) throw exc::engine_error("the double link list is inconsistent");
              if (q->left != p and q->left->exp >= q->exp) throw exc::engine_error("exponents are not increasing going to the right");
            }
 
          // Now we continue 
          p = p->val.down;
          if (p != nullptr)
            p = p->right;
        }
      else if (p->tag == Nmi_node::leaf)
        {
          p = p->right;
        }
    }
 
  return true;
}

References Nmi_node::leaf, mi, Nmi_node::node, and p.