Hyperarithmetical Sets
The central focus of hyperarithmetic theory are certain sets of natural numbers known as hyperarithmetic sets. There are three equivalent ways of defining this class of sets; the study of the relationships between these different definitions is one motivation for the study of hyperarithmetical theory.
Read more about this topic: Hyperarithmetical Theory
Famous quotes containing the word sets:
“It is mediocrity which makes laws and sets mantraps and spring-guns in the realm of free song, saying thus far shalt thou go and no further.”
—James Russell Lowell (1819–91)