/**
  * Applies the <b>(ATTR)</b> rule to the <code>pNode</code> using the <code>pContext</code>.
  *
  * @param pContext The big step proof pContext.
  * @param pNode The node to apply the <b>(ATTR)</b> rule to.
  */
 public void applyAttr(BigStepProofContext pContext, BigStepProofNode pNode) {
   Row row = (Row) pNode.getExpression();
   Expression[] rowExpressions = row.getExpressions();
   Attribute attribute = (Attribute) rowExpressions[0];
   pContext.addProofNode(pNode, attribute.getE());
   pContext.addProofNode(pNode, row.tailRow());
 }
 /**
  * Applies the <b>(SEND-SKIP)</b> rule to the <code>pNode</code> using the <code>pContext</code>.
  *
  * @param pContext The big step proof pContext.
  * @param pNode The node to apply the <b>(SEND-SKIP)</b> rule to.
  */
 public void applySendSkip(BigStepProofContext pContext, BigStepProofNode pNode) {
   Send send = (Send) pNode.getExpression();
   Row row = (Row) send.getE();
   if (!row.isValue()) {
     throw new IllegalArgumentException("Can not apply SEND-SKIP"); // $NON-NLS-1$
   }
   Expression[] rowExpressions = row.getExpressions();
   Identifier methodName;
   if (rowExpressions[0] instanceof Method) {
     Method method = (Method) rowExpressions[0];
     methodName = method.getId();
   } else if (rowExpressions[0] instanceof CurriedMethod) {
     CurriedMethod curriedMethod = (CurriedMethod) rowExpressions[0];
     methodName = curriedMethod.getIdentifiers()[0];
   } else {
     throw new IllegalArgumentException("Can not apply SEND-SKIP"); // $NON-NLS-1$
   }
   boolean definedLater = false;
   for (int i = 1; i < row.getExpressions().length; i++) {
     Expression rowChild = rowExpressions[i];
     if ((rowChild instanceof Method) && (((Method) rowChild).getId().equals(send.getId()))) {
       definedLater = true;
       break;
     } else if ((rowChild instanceof CurriedMethod)
         && (((CurriedMethod) rowChild).getIdentifiers()[0].equals(send.getId()))) {
       definedLater = true;
       break;
     }
   }
   if ((definedLater) || (!(send.getId().equals(methodName)))) {
     pContext.addProofNode(pNode, new Send(row.tailRow(), send.getId()));
   } else {
     throw new IllegalArgumentException("Can not apply SEND-SKIP"); // $NON-NLS-1$
   }
 }
 /**
  * Applies the <b>(METHOD)</b> rule to the <code>pNode</code> using the <code>pContext</code>.
  *
  * @param pContext The big step proof pContext.
  * @param pNode The node to apply the <b>(METHOD)</b> rule to.
  */
 public void applyMethod(BigStepProofContext pContext, BigStepProofNode pNode) {
   Row row = (Row) pNode.getExpression();
   Expression[] rowExpressions = row.getExpressions();
   if ((!(rowExpressions[0] instanceof Method))
       && (!(rowExpressions[0] instanceof CurriedMethod))) {
     throw new IllegalArgumentException("Can not apply METHOD"); // $NON-NLS-1$
   }
   pContext.addProofNode(pNode, row.tailRow());
 }