>I dedicate this book to my parents, Ayn Rand and God.

i think this is a bit ambiguous either way.  to add the comma would
make it:

	I dedicate this book to my parents, Ayn Rand, and God.

ie, a list, but to replace the comma would give:

	I dedicate this book to my parents: Ayn Rand and God.

which names your parents.  a single comma just strikes me as awkward
for both possible interpretations.

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