In mathematical logic and computer science, the μ-recursive functions are a class of partial functions from natural numbers to natural numbers that are "computable" in an intuitive sense. In fact, in computability theory it is shown that the μ-recursive functions are precisely the functions that can be computed by Turing machines. The μ-recursive functions are closely related to primitive recursive functions, and their inductive definition (below) builds upon that of the primitive recursive functions. However, not every μ-recursive function is a primitive recursive function—the most famous example...

Turtles All the Way Down is a upcoming novel by author John Green. It will be published on October 10, 2017. It will be his fifth solo novel, and his seventh overall. Its publication was announced during VidCon 2017, the online video conference co-founded by Green and his brother Hank. It is his first published work since his 2012 novel The Fault in Our Stars. == Plot summary == The story center arounds 16 year-old Aza Holmes, a high school student living with Obsessive-Compulsive Disorder, and her search for a fugitive billionaire. The only other details of the plot known to the public are that...