Change symbol "gamma" in Example 4.4, to "lambda"

[tmlouw]

In Example 4.4 on p 74, you use the Greek symbol "gamma" to indicate the regularization parameter. Earlier in the book (and in line with most discussions on regularization), the Greek symbol "lambda" is used. My suggestion is simply to change the symbol "gamma" to "lambda" in Example 4.4.

[andreas-lindholm]

Good suggestion, this has now been updated