Compaction of Church Numerals

In this study, we address the problem of compaction of Church numerals. Church numerals are unary representations of natural numbers on the scheme of lambda terms. We propose a novel decomposition scheme from a given natural number into an arithmetic expression using tetration, which enables us to o...

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Main Authors: Isamu Furuya, Takuya Kida
Format: Article
Language:English
Published: MDPI AG 2019-08-01
Series:Algorithms
Subjects:
Online Access:https://www.mdpi.com/1999-4893/12/8/159
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author Isamu Furuya
Takuya Kida
author_facet Isamu Furuya
Takuya Kida
author_sort Isamu Furuya
collection DOAJ
description In this study, we address the problem of compaction of Church numerals. Church numerals are unary representations of natural numbers on the scheme of lambda terms. We propose a novel decomposition scheme from a given natural number into an arithmetic expression using tetration, which enables us to obtain a compact representation of lambda terms that leads to the Church numeral of the natural number. For natural number <i>n</i>, we prove that the size of the lambda term obtained by the proposed method is <inline-formula> <math display="inline"> <semantics> <mrow> <mi mathvariant="script">O</mi> <mo stretchy="false">(</mo> <msup> <mrow> <mo stretchy="false">(</mo> <msub> <mi>slog</mi> <mn>2</mn> </msub> <mi>n</mi> <mo stretchy="false">)</mo> </mrow> <mrow> <mo stretchy="false">(</mo> <mo form="prefix">log</mo> <mi>n</mi> <mo>/</mo> <mo form="prefix">log</mo> <mrow> <mo form="prefix">log</mo> <mi>n</mi> </mrow> <mo stretchy="false">)</mo> </mrow> </msup> <mo stretchy="false">)</mo> </mrow> </semantics> </math> </inline-formula>. Moreover, we experimentally confirmed that the proposed method outperforms binary representation of Church numerals on average, when <i>n</i> is less than approximately 10,000.
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spelling doaj.art-e17b6ba63779470d814f00e1316988bc2022-12-22T03:04:38ZengMDPI AGAlgorithms1999-48932019-08-0112815910.3390/a12080159a12080159Compaction of Church NumeralsIsamu Furuya0Takuya Kida1Graduate School/Faculty of Information Science and Technology, Hokkaido University, Kita 14 Nishi 9, Sapporo 060-0814, JapanGraduate School/Faculty of Information Science and Technology, Hokkaido University, Kita 14 Nishi 9, Sapporo 060-0814, JapanIn this study, we address the problem of compaction of Church numerals. Church numerals are unary representations of natural numbers on the scheme of lambda terms. We propose a novel decomposition scheme from a given natural number into an arithmetic expression using tetration, which enables us to obtain a compact representation of lambda terms that leads to the Church numeral of the natural number. For natural number <i>n</i>, we prove that the size of the lambda term obtained by the proposed method is <inline-formula> <math display="inline"> <semantics> <mrow> <mi mathvariant="script">O</mi> <mo stretchy="false">(</mo> <msup> <mrow> <mo stretchy="false">(</mo> <msub> <mi>slog</mi> <mn>2</mn> </msub> <mi>n</mi> <mo stretchy="false">)</mo> </mrow> <mrow> <mo stretchy="false">(</mo> <mo form="prefix">log</mo> <mi>n</mi> <mo>/</mo> <mo form="prefix">log</mo> <mrow> <mo form="prefix">log</mo> <mi>n</mi> </mrow> <mo stretchy="false">)</mo> </mrow> </msup> <mo stretchy="false">)</mo> </mrow> </semantics> </math> </inline-formula>. Moreover, we experimentally confirmed that the proposed method outperforms binary representation of Church numerals on average, when <i>n</i> is less than approximately 10,000.https://www.mdpi.com/1999-4893/12/8/159loss-less compressionlambda termhigher-order compression
spellingShingle Isamu Furuya
Takuya Kida
Compaction of Church Numerals
Algorithms
loss-less compression
lambda term
higher-order compression
title Compaction of Church Numerals
title_full Compaction of Church Numerals
title_fullStr Compaction of Church Numerals
title_full_unstemmed Compaction of Church Numerals
title_short Compaction of Church Numerals
title_sort compaction of church numerals
topic loss-less compression
lambda term
higher-order compression
url https://www.mdpi.com/1999-4893/12/8/159
work_keys_str_mv AT isamufuruya compactionofchurchnumerals
AT takuyakida compactionofchurchnumerals