In computability theory a cylindric numbering is a special kind of numbering first introduced by Yuri L. Ershov in 1973.
then there exists a computable function
ν = μ ∘ f
is a cylindric numbering we can always find an injective
is called cylindric if That is if it is one-equivalent to its cylindrification A set
is called cylindric if its indicator function is a cylindric numbering.