/**
  * Updates the <code>node</code> to which <b>(DUPL-SUBSUME)</b> was applied previously.
  *
  * @param context the minimal typing proof context.
  * @param pNode the node to update according to <b>(DUPL-SUBSUME)</b>.
  */
 public void updateDuplSubsume(MinimalTypingProofContext context, MinimalTypingProofNode pNode) {
   MinimalTypingExpressionProofNode node = (MinimalTypingExpressionProofNode) pNode;
   Duplication duplication = (Duplication) node.getExpression();
   if (node.getChildCount() == 1 && node.getLastChild().isFinished()) {
     // generate new child node
     context.addProofNode(node, node.getEnvironment(), duplication.getExpressions()[0]);
   } else if (node.getChildCount() > 1 && node.getLastChild().isFinished()) {
     // check if a:tau und e:tau' tau'<: tau
     TypeEnvironment environment = node.getEnvironment();
     Identifier id = duplication.getIdentifiers()[node.getChildCount() - 2];
     MonoType tau = null;
     try {
       tau = (MonoType) environment.get(id);
     } catch (Exception e) {
       throw new RuntimeException(
           MessageFormat.format(
               Messages.getString("MinimalTypingException.9"), id.toString())); // $NON-NLS-1$
     }
     MonoType tau2 = node.getLastChild().getType();
     if (tau == null || tau2 == null)
       throw new RuntimeException(
           MessageFormat.format(
               Messages.getString("MinimalTypingException.2"),
               "self")); //$NON-NLS-1$ //$NON-NLS-2$
     try {
       subtypeInternal(tau, tau2);
       subtypeInternal(tau2, tau);
     } catch (Exception e) {
       throw new RuntimeException(
           MessageFormat.format(
               Messages.getString("MinimalTypingException.2"),
               "self")); //$NON-NLS-1$ //$NON-NLS-2$
     }
   }
   if (node.getChildCount() == duplication.getIdentifiers().length + 1) {
     // set the type of this node
     context.setNodeType(node, node.getFirstChild().getType());
     // all childs added, so nothing more to do
     return;
   }
   // generate new child node
   context.addProofNode(
       node, node.getEnvironment(), duplication.getExpressions()[node.getChildCount() - 1]);
 }
 /**
  * Updates the <code>node</code> to which <b>(METHOD-SUBSUME)</b> was applied previously.
  *
  * @param context the minimal typing proof context.
  * @param pNode the node to update according to <b>(METHOD-SUBSUME)</b>.
  */
 public void updateMethodSubsume(MinimalTypingProofContext context, MinimalTypingProofNode pNode) {
   MinimalTypingExpressionProofNode node = (MinimalTypingExpressionProofNode) pNode;
   Row row = (Row) node.getExpression();
   if (node.getChildCount() == 1 && node.getFirstChild().isFinished()) {
     if (row.getExpressions()[0] instanceof Method) {
       Method method = (Method) row.getExpressions()[0];
       // generate new child node
       context.addProofNode(node, node.getEnvironment(), method.getE());
     } else {
       CurriedMethod curriedMethod = (CurriedMethod) row.getExpressions()[0];
       Expression curriedMethodE = curriedMethod.getE();
       MonoType[] types = curriedMethod.getTypes();
       Identifier[] identifiers = curriedMethod.getIdentifiers();
       for (int n = identifiers.length - 1; n > 0; --n) {
         curriedMethodE = new Lambda(identifiers[n], types[n], curriedMethodE);
       }
       // generate new child node
       context.addProofNode(pNode, node.getEnvironment(), curriedMethodE);
     }
   } else if (node.getChildCount() == 2 && node.getChildAt(1).isFinished()) {
     // Create the tailRow and add it as Expression of a new Child
     Expression[] expressions = ((Row) node.getExpression()).getExpressions();
     Expression[] tailRow = new Expression[expressions.length - 1];
     for (int i = 1; i < expressions.length; i++) {
       tailRow[i - 1] = expressions[i];
     }
     Row newRow = new Row(tailRow);
     // generate new child node
     context.addProofNode(node, node.getEnvironment(), newRow);
   } else if (node.getChildCount() == 3 && node.getChildAt(2).isFinished()) {
     Expression expression = row.getExpressions()[0];
     MonoType type = node.getFirstChild().getType();
     // if type is a rec type, unfold to get a object type
     if (type instanceof RecType) {
       RecType rec = (RecType) type;
       type = rec.getTau().substitute(rec.getTypeName(), rec);
     }
     ObjectType object = (ObjectType) type;
     RowType rowType = (RowType) object.getPhi();
     Identifier[] identifiers = rowType.getIdentifiers();
     MonoType[] types2 = rowType.getTypes();
     if (expression instanceof Method) {
       Identifier m =
           (expression instanceof Method
               ? ((Method) expression).getId()
               : ((CurriedMethod) expression).getIdentifiers()[0]);
       MonoType tau = null;
       for (int i = 0; i < identifiers.length; i++) {
         if (m.equals(identifiers[i])) {
           tau = types2[i];
           break;
         }
       }
       if (tau == null)
         throw new RuntimeException(
             MessageFormat.format(
                 Messages.getString("MinimalTypingException.2"), m.toString())); // $NON-NLS-1$
       // generate new child node
       context.addProofNode(node, tau, node.getChildAt(1).getType());
     } else {
       CurriedMethod method = (CurriedMethod) expression;
       Identifier m = method.getIdentifiers()[0];
       type = types2[rowType.getIndexOfIdentifier(m)];
       MonoType[] types = method.getTypes();
       MonoType childType = node.getChildAt(1).getType();
       while (childType instanceof ArrowType) {
         childType = ((ArrowType) childType).getTau2();
       }
       ArrowType arrow = new ArrowType(types[types.length - 1], childType);
       for (int i = types.length - 2; i > 1; i--) {
         arrow = new ArrowType(types[i], arrow);
       }
       // generate new child node
       context.addProofNode(node, arrow, type);
     }
   } else if (node.getChildCount() == 4 && node.getChildAt(3).isFinished()) {
     Expression expression = row.getExpressions()[0];
     MonoType type = node.getChildAt(1).getType();
     while (type instanceof ArrowType) {
       type = ((ArrowType) type).getTau2();
     }
     MonoType type2 =
         (expression instanceof Method
             ? ((Method) expression).getTau()
             : ((CurriedMethod) expression).getTypes()[0]);
     if (type2 != null)
       // generate new child node
       context.addProofNode(node, type, type2);
     else {
       Identifier[] ids = new Identifier[1];
       ids[0] =
           (expression instanceof Method
               ? ((Method) expression).getIdentifiers()[0]
               : ((CurriedMethod) expression).getIdentifiers()[0]);
       MonoType[] types = {node.getChildAt(1).getType()};
       RowType rowType = new RowType(ids, types);
       RowType phi = (RowType) node.getChildAt(2).getType();
       rowType = RowType.union(rowType, phi);
       // set the type of this node
       context.setNodeType(node, rowType);
     }
   } else if (node.getChildCount() == 5 && node.getChildAt(4).isFinished()) {
     Expression expression = row.getExpressions()[0];
     Identifier[] ids = new Identifier[1];
     ids[0] =
         (expression instanceof Method
             ? ((Method) expression).getIdentifiers()[0]
             : ((CurriedMethod) expression).getIdentifiers()[0]);
     MonoType[] types = {node.getChildAt(1).getType()};
     RowType rowType = new RowType(ids, types);
     RowType phi = (RowType) node.getChildAt(2).getType();
     rowType = RowType.union(rowType, phi);
     // set the type of this node
     context.setNodeType(node, rowType);
   }
 }