  The book "Continuous-Time Markov Chains" by W. J. Anderson collects a large
part of the development in the past thirty years. It is now a popular reference
for the researchers on this subject or related fields. Unfortunately, due to a
misunderstanding of the approximating methods, several results in the book are
incorrectly stated or proved. Since the results are related to the present
author's work, to whom it may be a duty to correct the mistakes in order to
avoid further confusion. We emphasize the approximating methods because they
are useful in many situations.
