(*<*) (* Title: Theory ArithExtras.thy (FOCUS streams) Author: Maria Spichkova <maria.spichkova at rmit.edu.au>, 2013 *) (*>*) section "Theory ArithExtras.thy" theory ArithExtras imports Main begin datatype natInf = Fin nat | Infty (‹∞›) primrec nat2inat :: "nat list ⇒ natInf list" where "nat2inat [] = []" | "nat2inat (x#xs) = (Fin x) # (nat2inat xs)" end