▁interpretation ▁of ▁and ▁strongly ▁normal izing ▁rec ursor ▁for ▁Scott - encoded ▁numer als , ▁referring ▁to ▁them ▁as ▁the ▁" Stack ▁type " ▁representation ▁of ▁numbers . ▁Tor ben ▁M og ensen ▁later ▁extended ▁Scott ▁encoding ▁for ▁the ▁encoding ▁of ▁L ambda ▁terms ▁as ▁data . ▁ ▁Disc uss ion ▁ ▁L ambda ▁calculus ▁allows ▁data ▁to ▁be ▁stored ▁as ▁parameters ▁to ▁a ▁function ▁that ▁does ▁not ▁yet ▁have ▁all ▁the ▁parameters ▁required ▁for ▁application . ▁ ▁For ▁example , ▁▁▁▁ ▁May ▁be ▁thought ▁of ▁as ▁a ▁record ▁or ▁struct ▁where ▁the ▁fields ▁ ▁have ▁been ▁initialized ▁with ▁the ▁values ▁. ▁ ▁These ▁values ▁may ▁then ▁be ▁accessed ▁by ▁applying ▁the ▁term ▁to ▁a ▁function ▁f . ▁ ▁This ▁reduces ▁to , ▁▁▁▁ ▁c ▁may ▁represent ▁a ▁constructor ▁for ▁an ▁algebraic ▁data ▁type ▁in ▁functional ▁languages ▁such ▁as ▁H askell . ▁ ▁Now ▁suppose ▁there ▁are ▁N ▁construct ors , ▁each ▁with ▁ ▁arguments ; ▁ ▁Each ▁constructor ▁selects ▁a ▁different ▁function ▁from ▁the ▁function ▁parameters ▁. ▁This ▁provides ▁branch ing ▁in ▁the ▁process ▁flow , ▁based ▁on ▁the ▁constructor . ▁Each ▁constructor ▁may ▁have ▁a ▁different ▁ar ity ▁( number ▁of ▁parameters ). ▁ ▁If ▁the ▁construct ors ▁have ▁no ▁parameters ▁then ▁the ▁set ▁of ▁construct ors ▁acts ▁like ▁an ▁enum ; ▁a ▁type ▁with ▁a ▁fixed ▁number ▁of ▁values . ▁ ▁If ▁the ▁construct ors ▁have ▁parameters , ▁recursive ▁data ▁structures ▁may ▁be ▁constructed . ▁ ▁Definition ▁Let ▁D ▁be ▁a ▁dat atype ▁with ▁N ▁construct ors , ▁, ▁such