<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">OALibJ</journal-id><journal-title-group><journal-title>Open Access Library Journal</journal-title></journal-title-group><issn pub-type="epub">2333-9705</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/oalib.1106719</article-id><article-id pub-id-type="publisher-id">OALibJ-103005</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Biomedical&amp;Life Sciences</subject><subject> Business&amp;Economics</subject><subject> Chemistry&amp;Materials Science</subject><subject> Computer Science&amp;Communications</subject><subject> Earth&amp;Environmental Sciences</subject><subject> Engineering</subject><subject> Medicine&amp;Healthcare</subject><subject> Physics&amp;Mathematics</subject><subject> Social Sciences&amp;Humanities</subject></subj-group></article-categories><title-group><article-title>
 
 
  Subdivide the Shape of Numbers and a Theorem of Ring
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ji</surname><given-names>Peng</given-names></name><xref ref-type="aff" rid="aff1"><sub>1</sub></xref></contrib></contrib-group><aff id="aff1"><label>1</label><addr-line>Department of Electronic Information, Nanjing University, Nanjing, China</addr-line></aff><pub-date pub-type="epub"><day>01</day><month>09</month><year>2020</year></pub-date><volume>07</volume><issue>09</issue><fpage>1</fpage><lpage>14</lpage><history><date date-type="received"><day>17,</day>	<month>August</month>	<year>2020</year></date><date date-type="rev-recd"><day>19,</day>	<month>September</month>	<year>2020</year>	</date><date date-type="accepted"><day>22,</day>	<month>September</month>	<year>2020</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
  
    This article is based on the concept of Shape of numbers, introduce more shapes, obtain the calculation formulas and find an explanation of the formulas. By observing and associating, show a law about the symmetry of Ring. 
  
 
</p></abstract><kwd-group><kwd>Shape of Numbers</kwd><kwd> Calculation Formula</kwd><kwd> Symmetry</kwd><kwd> Combinatorics</kwd><kwd> Ring</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction</title><p>Peng, J. introduced the definition of Shape of numbers in [<xref ref-type="bibr" rid="scirp.103005-ref1">1</xref>]:</p><p>( K 1 , K 2 , ⋯ , K M ) , K i ∈ N , K 1 &lt; K 2 &lt; ⋯ &lt; K M</p><p>there are M-1 intervals between adjacent numbers. Use A for continuity and B for discontinuity, record as a string of M-1 characters (e.g. AABB…) to represents a catalog.</p><p>Define collection of a catalog as Shape of numbers. Use the symbol PX to represent a catelog (if M = 1 then PX = 1).</p><p>The single ( K 1 , K 2 , ⋯ , K M ) is an Item, K 1 K 2 ⋯ K M is the product of an item.</p><p>For example:</p><p>( 1 , 2 , 4 ) , ( 1 , 2 , 8 ) , ( 2 , 3 , 6 ) ∈ P X = A B , ( 1 , 3 , 5 ) , ( 1 , 3 , 6 ) , ( 2 , 4 , 6 ) ∈ P X = B B ,</p><p>( 1 , 2 , 5 , 6 ) , ( 2 , 3 , 6 , 7 ) , ( 2 , 3 , 7 , 8 ) , ( 1002 , 1003 , 6789 , 6790 ) ∈ P X = A B A</p><p>P M ( P X ) = Count of numbers of PX, P A ( P X ) = Count of A, P B ( P X ) = Count of B</p><p>→ P M ( P X ) = P A ( P X ) + P B ( P X ) + 1</p><p>| P X | = Count of items belonging to PX</p><p>M I N ( P X ) = Minimum product of PX: M I N ( A A ) = 1 &#215; 2 &#215; 3 , M I N ( A B ) = 1 &#215; 2 &#215; 4</p><p>I D X ( P X ) = 2 + P A ( P X ) + 2 &#215; P B ( P X ) = P M ( P X ) + P B ( P X ) + 1 : I D X ( A A ) = 4 , I D X ( A B ) = 5</p><p>S U M ( N , P X ) = Sum of all product of items belonging to PX in [ 1 , N − 1 ]</p><p>For example: S U M ( 6 , A B ) = 1 &#215; 2 &#215; 4 + 1 &#215; 2 &#215; 5 + 2 &#215; 3 &#215; 5</p><p>E N D ( N , P X ) = Set of items belonging to PX with the maximum factor = N-1</p><p>For example: E N D ( 6 , B ) = { ( 1 , 5 ) , ( 2 , 5 ) , ( 3 , 5 ) }</p><p>[<xref ref-type="bibr" rid="scirp.103005-ref1">1</xref>] obtain the conclusion:</p><p>| Itemsin S U M ( N , P X ) | = ( N − P M ( P X ) P B ( P X ) + 1 ) = ( N − I D X ( P X ) + P B ( P X ) + 1 P B ( P X ) + 1 ) (1)</p><p>S U M ( N , P X ) = M I N ( P X ) ( N I D X ( P X ) ) (2)</p><p>Definition: Subdividethe ( K 1 , K 2 , ⋯ , K M ) by interval of adjacent numbers. If the discontinuity interval is D &gt; 1, the interval of adjacent numbers ≥ D is classified into a same catelog. Use the symbol PY represent a catelog and represented by [min item]</p><p>For example:</p><p>P Y = [ 1 , 3 ] , ( 1 , 3 ) , ( 1 , 4 ) , ( 2 , 4 ) , ( 1 , 5 ) , ( 2 , 5 ) , ( 3 , 5 ) ∈ P Y . Same as PX = B</p><p>P Y = [ 1 , 4 ] , ( 1 , 4 ) , ( 1 , 5 ) , ( 2 , 5 ) , ( 1 , 6 ) , ( 2 , 6 ) , ( 3 , 6 ) ∈ P Y , ( 3 , 5 ) , ( 4 , 6 ) ∉ P Y</p><p>P Y = [ 1 , 4 , 6 ] , ( 1 , 4 , 7 ) , ( 1 , 5 , 7 ) , ( 2 , 5 , 7 ) ∈ P Y , ( 3 , 5 , 7 ) ∉ P Y</p><p>Redefinition: PB(PY) = Count of discontinuity intervals in PY, compatible with PX</p><p>Redefinition: IDX(PY) = The maximum factor of MIN(PY) + 1, compatible with PX</p><p>Definition: BASE(PY) = PX, If PB(PX) = PB(PY), PM(PX) = PM(PY), PX has discontinuity intervals at the same positions of PY.</p><p>For example:</p><p>P Y = [ 1 , 3 ] , [ 1 , 4 ] , [ 1 , K &gt; 2 ] ; B A S E ( P Y ) = [ 1 , 3 ] = B</p><p>P Y = [ 1 , 3 , 4 ] , [ 1 , 4 , 5 ] , [ 1 , K &gt; 2 , X = K + 1 ] ; B A S E ( P Y ) = [ 1 , 3 , 4 ] = B A</p><p>P Y = [ 1 , 3 , 5 ] , [ 1 , 4 , 9 ] , [ 1 , K &gt; 2 , X &gt; K + 1 ] ; B A S E ( P Y ) = [ 1 , 3 , 5 ] = B B</p><p>Definition: if f ( n ) = ∑ K i ( N − n i m i ) , then D 1 f ( n ) = ∑ K i ( N − n i − 1 m i − 1 )</p><p>Definition: P H ( P Y ) = I D X ( P Y ) − P B ( P Y ) − 2 = Maximum factor of M I N ( P Y ) − P B ( P Y ) − 1</p><p>P Y = [ 1 , K 1 ⋯ K M ] , B S = B A S E ( P Y ) = [ 1 , G 1 ⋯ G M ] →</p><p>P H ( P Y ) = K M − I D X ( B S ) + P M ( B S ) (1.0)</p><p>[Proof]</p><p>P H ( P Y ) = K M − P B ( P Y ) − 1 = K M − P B ( B S ) − 1 = K M − G M + M = K M − ( G M + 1 ) + ( M + 1 ) = Right</p><p>∑ n = K N − 1 n ( n − K M ) = ( M + 1 ) ( N − K M + 2 ) + ( M + K ) ( N − K M + 1 ) (1.1)</p><p>[Proof]</p><p>Left = ∑ n = K N − 1 ( n − K + 1 ) ( n − K M ) + ( K − 1 ) ∑ n = K N − 1 ( n − K M ) = ∑ n = K N − 1 ( M + 1 ) ( n − K + 1 M + 1 ) + ( K − 1 ) ∑ n = K N − 1 ( n − K M ) = ( M + 1 ) ( N − K + 1 M + 2 ) + ( K − 1 ) ( N − K M + 1 ) = ( M + 1 ) ( N − K M + 2 ) + ( M + 1 ) ( N − K M + 1 ) + ( K − 1 ) ( N − K M + 1 ) = Right</p><p>By definition:</p><p>S U M ( N , P Y ) = ∑ n = 0 N ∑ E N D ( n , P Y ) (1.2)</p><p>Derived from (1.2)</p><p>∑ E N D ( N , P Y ) = D 1 S U M ( N , P Y ) (1.3)</p><p>By definition:</p><p>S U M ( N , [ 1 , ⋯ , K , K + 1 ] ) = ∑ n = 0 N − 1 n &#215; ∑ E N D ( n , [ 1 , ⋯ , K ] ) (1.4)</p><p>S U M ( N , [ 1 , ⋯ , K , X &gt; K + 1 ] ) = ∑ n = 0 N − 1 n &#215; S U M ( n − X + K + 1 , [ 1 , ⋯ , K ] ) (1.5)</p><p>According to the method in [<xref ref-type="bibr" rid="scirp.103005-ref1">1</xref>]:</p><p>| Itemsin S U M ( N , P Y ) | = ( N − I D X ( P Y ) + P B ( P Y ) + 1 P B ( P Y ) + 1 ) = ( N − P H ( P Y ) − 1 P B ( P Y ) + 1 ) , (1.6)</p><p>compatible with (1).</p></sec><sec id="s2"><title>2. Calculation Formula</title><p>If P Y = B A S E ( P Y ) , the calculation formula has been given by (2).</p><p>Otherwise, it can be deduced from (1.1)-(1.5).</p><p>S U M ( N , [ 1 , K ≥ 3 ] ) = 3 ( N − K + 2 4 ) + K ( N − K + 2 3 ) (2.1)</p><p>[Proof]</p><p>Left → 1.2 ) ∑ n = 0 N ∑ E N D ( n , [ 1 , K ] ) = ∑ n = K + 1 N ( n − 1 ) ( 1 + 2 + ⋯ + ( n − K ) ) = ∑ n = K + 1 N ( n − 1 ) ( n − K + 1 2 ) = ∑ n = K N − 1 n ( n − K + 2 2 ) → 1.1 ) Right</p><p>S U M ( N , [ 1 , 2 , K &gt; 3 ] ) = 2 &#215; 4 ( N − K + 3 5 ) + 2 &#215; K ( N − K + 3 4 ) (2.2)</p><p>[Proof]</p><p>→ 1.5 ) ∑ n = 0 N − 1 n &#215; S U M ( n − K + 3 , [ 1 , 2 ] ) → ( 2 ) ∑ n = 0 N − 1 n &#215; 2 ( n − K + 3 3 ) → 1.1 ) Right</p><p>S U M ( N , [ 1 , K ≥ 3 , X = K + 1 ] ) = 12 ( N − X + 2 5 ) + 3 ( X + 1 ) ( N − X + 2 4 )       + 3 K ( N − X + 2 4 ) + K X ( N − X + 2 3 ) (2.3)</p><p>[Proof]</p><p>→ 1.2 )   1.4 )   2.1 ) ∑ n = 0 N − 1 n &#215; D 1 [ 3 ( n − K + 2 4 ) + K ( n − K + 2 3 ) ] = ∑ n = 0 N − 1 n &#215; [ 3 ( n − K + 1 3 ) + K ( n − K + 1 2 ) ] → 1.1 ) = 12 ( N − K + 1 5 ) + 3 ( K + 2 ) ( N − K + 1 4 ) + 3 K ( N − K + 1 4 )         + K ( K + 1 ) ( N − K + 1 3 ) = Right</p><p>S U M ( N , [ 1 , K ≥ 3 , X &gt; K + 1 ] ) = 15 ( N − X + 3 6 ) + 3 ( X + 1 ) ( N − X + 3 5 )         + 4 K ( N − X + 3 5 ) + K X ( N − X + 3 4 ) (2.4)</p><p>[Proof]</p><p>→ 1.5 )   2.1 ) ∑ n = 0 N − 1 n &#215; [ 3 ( n − X + 3 4 ) + K ( n − X + 3 3 ) ] → 1.1 ) Right</p><sec id="s2_1"><title>2.1. S U M ( N , [ 1 , K 1 ≥ 3 , ⋯ , K M ] )</title><p>P Y = [ 1 , K 1 ≥ 3 , ⋯ , K M ] , B A S E ( P Y ) = B S = [ 1 , G 1 , ⋯ , G M ]</p><p>1*) S U M ( N , P Y ) = ∑ A i ( P M i ) , 2 M items in total.</p><p>2*) M i = I D X ( B S ) , I D X ( B S ) − 1 , ⋯ , I D X ( B S ) − M</p><p>3*) P = N − P H ( P Y )</p><p>Use the form ( G 1 + K 1 ) ( G 2 + K 2 ) ⋯ ( G M + K M ) = ∑ X 1 X 2 ⋯ X M . The expansion function has 2<sup>M</sup> items in total.<sub> </sub></p><p>4*) M i = I D X ( B S ) − ( Count   of   X ∈ K )</p><p>5*) A i = ∏ i = 1 M ( X i + D i ) ,</p><p>D i = { − m , X i ∈ G , m = countof   { X i ⋯ X i − 1 } ∈ K       5.1 * ) + m , X i ∈ K , m = countof   { X i ⋯ X i − 1 } ∈ G       5.2 * )</p><p>[Proof]</p><p>P Y = [ 1 , K 1 ≥ 3 , ⋯ , K M ] , B S = B A S E ( P Y )</p><p>Suppose S U M ( N , P Y ) = ∑ X 1 ⋯ X M ( P M i ) , P = N − P H ( P Y ) .</p><p>According to inductive hypothesis:</p><p>( G 1 + K 1 ) ( G 2 + K 2 ) ⋯ ( G M + K M ) { ( G M + 1 ) + ( K M + 1 ) } = ∑ X 1 X 2 ⋯ X M { ( G M + 1 ) + ( K M + 1 ) }</p><p>C = Count   of   X ∈ K , M − C = Count   of   X ∈ G , M i = I D X ( B S ) − C</p><p>P Y 1 = [ P Y , K M + 1 ] , B S 1 = B A S E ( P Y 1 ) (2.1.1)</p><p>S U M ( N , P Y 1 ) → 1 , 2 )   1.3 ) ∑ n = 0 N − 1 n &#215; D 1 S U M ( n , P Y ) = ∑ n = 0 N − 1 n &#215; ∑ X 1 ⋯ X M ( P − 1 M i − 1 ) → 1.1 ) = ∑ ​ ( X 1 ⋯ X M M i ( P − 1 M i + 1 ) + X 1 ⋯ X M ( P H ( P Y ) + M i ) ( P − 1 M i ) ) = ∑ X 1 ⋯ X M ( I D X ( B S ) − C ) ( P − 1 M i + 1 )     + ∑ X 1 ⋯ X M ( P H ( P Y ) + I D X ( B S ) − C ) ( P − 1 M i )</p><p>= ∑ X 1 ⋯ X M ( ( G M + 1 ) − C ) ( P − 1 M i + 1 )     + ∑ X 1 ⋯ X M ( ( K M + 1 ) + ( P M ( B S ) − 1 ) − C ) ( P − 1 M i ) = ∑ X 1 ⋯ X M ( G M + 1 − C ) ( P − 1 I D X ( B S ) − C + 1 )     + ∑ X 1 ⋯ X M ( K M + 1 + M − C ) ( P − 1 I D X ( B S ) − C )</p><p>= ∑ X 1 ⋯ X M ( G M + 1 − C ) ( P − 1 I D X ( B S 1 ) − C )     + ∑ X 1 ⋯ X M ( K M + 1 + M − C ) ( P − 1 I D X ( B S 1 ) − ( C + 1 ) )</p><p>1*) is obvious.</p><p>M<sub>i</sub> change form I D X ( B S ) , ⋯ , I D X ( B S ) − M to I D X ( B S ) + 1 , ⋯ , I D X ( B S ) − M = I D X ( B S 1 ) , ⋯ , I D X ( B S 1 ) − ( M + 1 )</p><p>2*) proved</p><p>P − 1 = N − P H ( P Y ) − 1 = N − ( K M − I D X ( B S ) + P M ( B S ) ) − 1 = N − { ( K M + 1 ) − ( I D X ( B S ) + 1 ) + ( P M ( B S ) + 1 ) } = N − ( K M + 1 − I D X ( B S 1 ) + P M ( B S 1 ) ) = N − P H ( P Y 1 )</p><p>3*) proved</p><p>X 1 ⋯ X M ( G M + 1 − C ) ( P − 1 I D X ( B S 1 ) − C ) → 4*) 5.1*)</p><p>X 1 ⋯ X M ( G M + 1 − C ) ( P − 1 I D X ( B S 1 ) − ( C + 1 ) ) → 4*) 5.2*)</p><p>4*) 5*) proved</p><p>P Y 1 = [ P Y , K M + 1 &gt; K M + 1 ] , B S 1 = B A S E ( P Y 1 ) (2.1.2)</p><p>S U M ( N , P Y 1 ) → 1.5 ) ∑ n = 0 N − 1 n &#215; S U M ( n − K M + 1 + K M + 1 , P Y ) = ∑ n = 0 N − 1 n &#215; ∑ X 1 ⋯ X M ( n − K M + 1 + K M + 1 − P H ( P Y ) M i ) = ∑ n = 0 N − 1 n &#215; ∑ X 1 ⋯ X M ( n − K M + 1 + K M + 1 − ( K M − I D X ( B S ) + P M ( B S ) ) M i ) = ∑ n = 0 N − 1 n &#215; ∑ X 1 ⋯ X M ( n − ( K M + 1 − I D X ( B S ) + P M ( B S ) − 1 ) M i )</p><p>= ∑ X 1 ⋯ X M ( M i + 1 ) ( P 1 M i + 2 )     + ∑ X 1 ⋯ X M ( K M + 1 − I D X ( B S ) + M + M i ) ( P 1 M i + 1 ) = ∑ X 1 ⋯ X M ( I D X ( B S ) − C + 1 ) ( P 1 M i + 2 )     + ∑ X 1 ⋯ X M ( K M + 1 + M − C ) ( P 1 M i + 1 )</p><p>= ∑ X 1 ⋯ X M ( G M + 1 − C ) ( P 1 I D X ( B S ) − C + 2 )     + ∑ X 1 ⋯ X M ( K M + 1 + M − C ) ( P 1 I D X ( B S ) − C + 1 ) = ∑ X 1 ⋯ X M ( G M + 1 − C ) ( P 1 I D X ( B S 1 ) − C )     + ∑ X 1 ⋯ X M ( K M + 1 + M − C ) ( P 1 I D X ( B S 1 ) − ( C + 1 ) )</p><p>1*) is obvious.</p><p>M<sub>i</sub> change form I D X ( B S ) , ⋯ , I D X ( B S ) − M to I D X ( B S ) + 2 , ⋯ , I D X ( B S ) − M + 1 = I D X ( B S 1 ) , ⋯ , I D X ( B S 1 ) − ( M + 1 )</p><p>2*) proved</p><p>P 1 = N − { K M + 1 − ( I D X ( B S ) + 2 ) + ( P M ( B S ) + 1 ) } = N − P H ( P Y 1 )</p><p>3*) proved</p><p>X 1 ⋯ X M ( G M + 1 − C ) ( P 1 I D X ( B S 1 ) − C ) → 4*) 5.1*)</p><p>X 1 ⋯ X M ( K M + 1 + M − C ) ( P 1 I D X ( B S 1 ) − ( C + 1 ) ) → 4*) 5.2*)</p><p>4*) 5*) proved</p><p>q.e.d.</p><p>Example 2.1:</p><p>( 3 + K 1 ) ( 5 + K 2 ) ( 7 + K 3 ) = 3 &#215; 5 &#215; 7 + 3 &#215; 5 &#215; K 3 + 3 &#215; K 2 &#215; 7 + 3 &#215; K 2 &#215; K 3 + K 1 &#215; 5 &#215; 7         + K 1 &#215; 5 &#215; K 3 + K 1 &#215; K 2 &#215; 7 + K 1 &#215; K 2 &#215; K 3</p><p>P = N − K 3 + I D X ( [ 1 , 3 , 5 , 7 ] ) − P M ( [ 1 , 3 , 5 , 7 ] ) = N − K 3 + 8 − 4 = N − K 3 + 4</p><p>S U M ( N , [ 1 , K 1 ≥ 3 , K 2 ≥ K 1 + 2 , K 3 ≥ K 2 + 2 ] ) = 3 &#215; 5 &#215; 7 ( P 8 ) + 3 &#215; 5 &#215; ( K 3 + 2 ) ( P 7 ) + 3 &#215; ( K 2 + 1 ) &#215; ( 7 − 1 ) ( P 7 )     + 3 &#215; ( K 2 + 1 ) &#215; ( K 3 + 1 ) ( P 7 ) + K 1 &#215; ( 5 − 1 ) &#215; ( 7 − 1 ) ( P 7 )     + K 1 &#215; ( 5 − 1 ) &#215; ( K 3 + 1 ) ( P 6 ) + K 1 &#215; K 2 &#215; ( 7 − 2 ) ( P 6 )       + K 1 &#215; K 2 &#215; K 3 ( P 5 )</p></sec><sec id="s2_2"><title>2.2. S U M ( N , [ 1 , 2 , ⋯ , n , K 1 ≥ n + 2 , ⋯ , K M ] )</title><p>P Y = [ 1 , 2 , 3 , ⋯ , n , K 1 ≥ n + 2 , ⋯ , K M ] ,</p><p>B A S E ( P Y ) = B S = [ 1 , 2 , 3 , ⋯ , n , G 1 , ⋯ , G M ]</p><p>1*) S U M ( N , P Y ) = ∑ A i ( P M i ) , 2 M items in total.</p><p>2*) M i = I D X ( B S ) , I D X ( B S ) − 1 , ⋯ , I D X ( B S ) − M</p><p>3*) P = N   −   K M   +   I D X ( B S ) − ( M   + 1 ) = N   − ( K M   −   P B ( P Y ) − 1 ) = N   −   P H ( P Y )</p><p>Use the form ( G 1 + K 1 ) ( G 2 + K 2 ) ⋯ ( G M + K M ) = ∑ X 1 X 2 ⋯ X M .</p><p>4*) M i = I D X ( B S ) − ( Countof   X ∈ K )</p><p>5*) A i = n ! &#215; (Same as 2.1)</p><p>Example 2.2:</p><p>( 5 + K 1 ) ( 7 + K 2 ) = 5 &#215; 7 + 5 &#215; K 2 + K 1 &#215; 7 + K 1 &#215; K 2 , P = N − K 2 + I D X ( [ 1 , 2 , 3 , 5 , 7 ] ) − 3 = N − K 2 + 5</p><p>S U M ( N , [ 1 , 2 , 3 , K 1 ≥ 5 , K 2 ≥ K 1 + 2 ] ) = 3 ! { 5 &#215; 7 ( P 8 ) + 5 &#215; ( K 2 + 1 ) ( P 7 ) + K 1 &#215; ( 7 − 1 ) ( P 7 ) + K 1 K 2 ( P 6 ) }</p></sec><sec id="s2_3"><title>2.3. The Meaning of the Expansion of SUM (N, PY)</title><p>P Y = [ 1 , K 1 , ⋯ , K M ] , anItem = { begin , K 1 + E 1 , ⋯ , K M + E M }</p><p>( productofanitem ) = begin &#215; ( K 1 + E 1 ) ⋯ ( K M + E M ) = begin &#215; ∑ F 1 ⋯ F M <sub> </sub></p><p>F i = E (means F i = E i ) or F i = K i ,</p><p>S U M ( N , P Y ) = ∑ product = ∑ ∑ begin &#215; F 1 ⋯ F M (2.3.1*)</p><p>Define 2.3. S U M _ K ( N , P Y , P F = F 1 F 2 ⋯ F M ) = ∑ Items in (2.3.1*) with the same PF</p><p>Example 2.3:</p><p>S U M ( N , [ 1 , K 1 ≥ 3 , K 2 ≥ K 1 + 2 ] ) = 15 ( N − K 2 + 3 6 ) + 3 ( K 2 + 1 ) ( N − K 2 + 3 5 )         + 4 K 1 ( N − K 2 + 3 5 ) + K 1 K 2 ( N − K 2 + 3 4 ) = 15 ( N − K 2 + 3 6 ) + 3 ( N − K 2 + 3 5 ) + 3 K 2 ( N − K 2 + 3 5 )         + 4 K 1 ( N − K 2 + 3 5 ) + K 1 K 2 ( N − K 2 + 3 4 ) = ∑ n = 0 N − K 2 ∑ n &#215; ( K 1 + E 1 , i ) ( K 2 + E 2 , i )</p><p>then can prove</p><p>S U M _ K ( N , P Y , E E ) = ∑ allitems begin ∗ E 1 , i E 2 , i = 15 ( N − K 2 + 3 6 ) + 3 ( N − K 2 + 3 5 )</p><p>S U M _ K ( N , P Y , K 1 E ) = ∑ allitems begin ∗ K 1 E 2 , i = 4 K 1 ( N − K 2 + 3 5 )</p><p>S U M _ K ( N , P Y , E K 2 ) = ∑ allitems begin ∗ E 1 , i K 2 = 3 K 2 ( N − K 2 + 3 5 )</p><p>S U M _ K ( N , P Y , K 1 K 2 ) = ∑ allitems begin ∗ K 1 K 2 = K 1 K 2 ( N − K 2 + 3 4 )</p><p>S U M ( N , P Y ) = ∑ ∏ i = 1 M ( X i + D i ) ( P M i ) ,</p><p>X i + D i = { { G i − D i } , X i ∈ G , D i = countof   { X 1 ⋯ X i − 1 } ∈ K { K i } + { D i } , X i ∈ K , D i = countof   { X 1 ⋯ X i − 1 } ∈ G (2.3.2*)</p><p>Theorem 2.3 S U M _ K ( N , P Y , P F ) = ∑ Items in (2.3.2*) expand by {}, factors has the same { K i } ∈ F</p><p>= ∑ ∏ i = 1 M Y i ( P M i ) ,</p><p>Y i = { 0 , F i ∈ K , X i ∈ G K i , F i ∈ K , X i ∈ K G i − D i , F i = E , X i ∈ G , D i = countof   { ⋯ X i − 1 } ∈ K D i , F i = E , X i ∈ K , D i = countof   { ⋯ X i − 1 } ∈ G (2.3.3*)</p><p>P = N − P H ( P Y ) , M i = I D X ( B S ) − ( Count   of   X ∈ K )</p><p>[Proof]</p><p>Suppose S U M _ K ( N , P Y , P Z ) = ∑ ∏ i = 1 M Y i ( P M i ) , P = N − P H ( P Y ) .</p><p>P Y 1 = [ P Y , K M + 1 ] , C = Count   of   X ∈ K ,</p><p>M − C = Count   of   X ∈ G , M i = I D X ( B S ) − C</p><p>When K M + 1 = K M + 1</p><p>S U M ( N , P Y 1 ) → 1 , 2 )   1.3 ) ∑ n = 0 N − 1 n &#215; D 1 S U M ( n , P Y ) → ∑ n = 0 N − 1 n &#215; D 1 S U M _ K ( n , P Y , P F ) = ∑ n = 0 N − 1 n &#215; ∑ ∏ i = 1 M Y i ( P − 1 M i − 1 ) → reference   ( 2.1.1 )</p><p>= ∑ ∏ i = 1 M Y i ( G M + 1 − C ) ( P − 1 I D X ( B S 1 ) − C )     + ∑ ∏ i = 1 M Y i ( M − C ) ( P − 1 I D X ( B S 1 ) − ( C + 1 ) )     + ∑ ∏ i = 1 M Y i K M + 1 ( P − 1 I D X ( B S 1 ) − ( C + 1 ) ) = S U M _ K ( N , P Y 1 , [ P F , E ] ) + S U M _ K ( N , P Y 1 , [ P F , K M + 1 ] )</p><p>P − 1 = N − P H ( P Y 1 ) → (2.3.3*)</p><p>S U M _ K ( N , P Y 1 , [ P F , K M + 1 ] ) = ∑ ∏ i = 1 M Y i K M + 1 ( P − 1 I D X ( B S 1 ) − ( C + 1 ) ) → (2.3.3*)</p><p>S U M _ K ( N , P Y 1 , [ P F , E ] ) = ∑ ∏ i = 1 M Y i ( G M + 1 − C ) ( P − 1 I D X ( B S 1 ) − C )</p><p>    + ∑ ∏ i = 1 M Y i ( M − C ) ( P − 1 I D X ( B S 1 ) − ( C + 1 ) ) → (2.3.3*)</p><p>When K M + 1 &gt; K M + 1</p><p>S U M ( N , P Y 1 ) → 1 , 5 ) ∑ n = 0 N − 1 n &#215; S U M ( n − K M + 1 + K M + 1 , P Y ) → ∑ n = 0 N − 1 n &#215; S U M _ K ( n − K M + 1 + K M + 1 , P Y , P F ) = ∑ n = 0 N − 1 n &#215; ∑ ∏ i = 1 M Y i ( P 1 M i ) → reference   ( 2.1.2 )</p><p>= ∑ ∏ i = 1 M Y i ( G M + 1 − C ) ( P 1 I D X ( B S 1 ) − C )     + ∑ ∏ i = 1 M Y i ( M − C ) ( P 1 I D X ( B S 1 ) − ( C + 1 ) )     + ∑ ∏ i = 1 M Y i K M + 1 ( P 1 I D X ( B S 1 ) − ( C + 1 ) ) = S U M _ K ( N , P Y 1 , [ P F , E ] ) + S U M _ K ( N , P Y 1 , [ P F , K M + 1 ] )</p><p>P 1 = N − P H ( P Y 1 ) → (2.3.3*)</p><p>S U M _ K ( N , P Y 1 , [ P F , K M + 1 ] ) = ∑ ∏ i = 1 M Y i K M + 1 ( P 1 I D X ( B S 1 ) − ( C + 1 ) ) → (2.3.3*)</p><p>S U M _ K ( N , P Y 1 , [ P F , E ] ) = ∑ ∏ i = 1 M Y i ( G M + 1 − C ) ( P 1 I D X ( B S 1 ) − C )</p><p>      + ∑ ∏ i = 1 M Y i ( M − C ) ( P 1 I D X ( B S 1 ) − ( C + 1 ) ) → (2.3.3*)</p><p>q.e.d.</p><p>2.3.1) S U M _ K ( N , P Y = [ 1 , 2 , ⋯ , n , K 1 ≥ n + 2 , ⋯ , K M ] , P F ) has the similar conclusions.</p><p>2.3.2) S U M _ K ( N , P Y = [ 1 , 2 , ⋯ , n , K 1 ≥ n + 2 , ⋯ , K M ] , K 1 K 2 ⋯ K M ) ,</p><p>B S = B A S E ( P Y ) = M I N ( P Y ) ( N − P H ( P Y ) I D X ( B S ) − M ) = M I N ( P Y ) ∑ n = 0 N − 1 ( n − P H ( P Y ) − 1 I D X ( B S ) − M − 1 ) = M I N ( P Y ) ∑ n = 0 N − 1 ( n − P H ( P Y ) − 1 P B ( B S ) + 1 ) = M I N ( P Y ) ∑ n = 0 N − 1 ( n − P H ( P Y ) − 1 P B ( P Y ) + 1 ) = M I N ( P Y ) ∑ n = 0 N − 1 | Itemsin S U M ( n + 1 , P Y ) |</p><p>3. A Theorem of Ring</p><p>P Y = [ 1 , K 1 ≥ 3 , ⋯ , K M ] , B A S E ( P Y ) = B S = [ 1 , G 1 , ⋯ , G M ]</p><p>S U M ( N , P Y ) = ∑ A i ( P M i ) ,</p><p>When PY = BS, S U M ( N , P Y ) = M I N ( B S ) ( N I D X ( B S ) )</p><p>This inspired us:</p><p>In the form ( G 1 + K 1 ) ( G 2 + K 2 ) ⋯ ( G M + K M ) , K i = G i → M I N ( B S ) | ∑ A i <sub> </sub>(M<sub>i</sub> is same).</p><p>Definition 3.1:</p><p>S , { K i } ∈ Ring ; K i = K j , K i &lt; K j , K i &gt; K j are allowed.</p><p>Choice N from ( K 1 , K 2 , ⋯ , K M ) , R = R 1 ⋯ R M</p><p>R i = + 1 Indicates that K<sub>i</sub> was selected, R i = − 1 Indicates that K<sub>i</sub> was unselected,</p><p>F ( N , M , R , K , S ) = ∏ i = 1 M ( K i + D i ) ,</p><p>D i = { − m S , R i = − 1 , m = count   of   { K 1 , ⋯ , K i − 1 }   selected + m S , R i = + 1 , m = count   of   { K 1 , ⋯ , K i − 1 }   unselected (*)</p><p>When S = 1, abbreviated as F ( N , M , R , K )</p><p>Definition 3.2:</p><p>H ( N 1 , N 2 , K , S ) = ∑ F ( N 1 , N 1 + N 2 , R , K , S ) , Sum traverses all N<sub>1</sub>-Choice of K</p><p>Theorem 3.1: H ( N 1 , N 2 , K , S ) = ( M N 1 , N 2 ) K 1 ⋯ K M , M = N 1 + N 2</p><p>[Proof]</p><p>When N 1 = 0 or N 2 = 0 , it is obvious.</p><p>H ( 1 , 1 , K , S ) = select   K 1 + select   K 2 = unselect   K 2 + select   K 2 = K 1 ( K 2 − S ) + K 1 ( K 2 + S ) = 2 K 1 K 2 <sub> </sub></p><p>Suppose H ( 1 , M − 1 , K , S ) = ( M 1 ) K 1 ⋯ K M</p><p>H ( 1 , M , K , S ) = select   K M + 1 + unselect   K M + 1 = H ( 0 , M , K , S ) ( K M + 1 + M S ) + H ( 1 , M − 1 , K , S ) ( K M + 1 − S ) = ( M 0 ) K 1 ⋯ K M ( K M + 1 + M S ) + ( M 1 ) K 1 ⋯ K M ( K M + 1 − S ) = { ( M 0 ) + ( M 1 ) } K 1 ⋯ K M K M + 1 + { M ( M 0 ) − ( M 1 ) } S &#215; K 1 ⋯ K M K M + 1 = ( M + 1 1 ) K 1 ⋯ K M K M + 1 <sub> </sub></p><p>→ H ( 1 , N 2 , K , S ) holds → Symmetry → H ( N 2 , 1 , K , S ) holds</p><p>Suppose H ( N 1 , M − N 1 , K , S ) = ( M N 1 ) K 1 ⋯ K M</p><p>H ( N 1 + 1 , M − N 1 , K , S ) = select   K M + 1 + unselect   K M + 1 = H ( N 1 , M − N 1 , K , S ) ( K M + 1 + ( M − N 1 ) S )         + H ( N 1 + 1 , M − N 1 − 1 , K , S ) ( K M + 1 − ( N 1 + 1 ) S ) = ( M N 1 ) K 1 ⋯ K M ( K M + 1 + ( M − N 1 ) S )     + ( M N 1 + 1 ) K 1 ⋯ K M ( K M + 1 − ( N 1 + 1 ) S )</p><p>= { ( M N 1 ) + ( M N 1 + 1 ) } K 1 ⋯ K M + 1         + { ( M − N 1 ) ( M N 1 ) − ( N 1 + 1 ) ( M N 1 + 1 ) } S &#215; K 1 ⋯ K M + 1 = ( M + 1 N 1 + 1 ) K 1 ⋯ K M K M + 1</p><p>→ H ( N 1 , N 2 , K , S ) holds</p><p>q.e.d.</p><p>Example 3.1: { K 1 , K 2 , K 3 } = { A , B , C }</p><p>H ( 1 , 2 , K ) = select   A + select   B + select   C = A ( B − 1 ) ( C − 1 ) + A ( B + 1 ) ( C − 1 ) + A B ( C + 2 ) = 3 A B C</p><p>H ( 2 , 1 , K ) = select   A B + select   B C + select   A C = A B ( C − 2 ) + A ( B + 1 ) ( C + 1 ) + A ( B − 1 ) ( C + 1 ) = 3 A B C</p><p>Definition 3.3:</p><p>K<sub>i</sub> come from q sources: S 1 , S 2 , ⋯ , S q , K i ∈ S j indicates K<sub>i</sub> come from S<sub>j</sub> d i f f ( K i , K j ) = d i f f ( K i ∈ S a , K j ∈ S b ) = d i f f ( a , b ) , d i f f ( a , b ) = S , ( a ≠ b ); d i f f ( a , b ) = − d i f f ( b , a ) ; d i f f ( a , a ) = 0 then can change related parts of definition 3.1 to</p><p>∏ i = 1 M ( K i + D i ) , D i = ∑ j &lt; i d i f f ( K i , K j )</p><p>and define H ( N 1 , N 2 , ⋯ , N q , K , S )</p><p>Theorem 3.2 H ( N 1 , N 2 , ⋯ , N q , K , S ) = ( M N 1 , N 2 , ⋯ , N q ) K 1 ⋯ K M , M = N 1 + N 2 + ⋯ + N q</p><p>[Proof]</p><p>Only need to prove S=1, and specify d i f f ( a , b ) = 1 , ( a &lt; b ) H ( N 1 , N 2 , K ) = ∑ Item , K i ∈ { S 1 , S 2 } . An item has M factors,</p><p>Choice N<sub>1</sub> factors, K<sub>i</sub> in these factors, K i ∈ S 1 , It is called invariant factor{F}.</p><p>Others are called variable factors {V}</p><p>L 2 + L 3 = N 2 , choice L<sub>2 </sub>factors in {V} to S<sub>2</sub>, L<sub>3</sub> to S<sub>3 </sub></p><p>By definition, H ( L 2 , L 3 , V ) = ∑ { ( L 2 , L 3 ) − Choice   of   V }</p><p>∑ ( ∏ { F } &#215; ∑ { ( L 2 , L 3 ) − Choice   of   V } ) = ∑ ( ∏ { F } &#215; H ( L 2 , L 3 , V ) ) = ∑ ( ∏ { F } &#215; ( N 2 L 1 , L 2 ) &#215; ∏ { V } ) = ( N 2 L 2 , L 3 ) ∑ Item = ( N 2 L 2 , L 3 ) ( M N 1 , N 2 ) K 1 ⋯ K M = ( M N 1 , L 2 , L 3 ) K 1 ⋯ K M = H ( N 1 , L 2 , L 3 , K )</p><p>and items gives all (N<sub>1</sub>, L<sub>2</sub>, L<sub>3</sub>)-Choice of K.</p><p>Prove ∑ ( ∏ { F } &#215; ∑ { ( L 2 , L 3 ) − Choice   of   V } ) satisfies the definition of H ( N 1 , ⋯ , K )</p><p>Let Item = ∏ i = 1 M ( K i + D i ) , ( anitemchanged ) = ∏ i = 1 M ( H i + E i ) , K i = H i <sub> </sub></p><p>A 1 = Count   of   { K 1 , ⋯ , K i − 1 } ∈ S 1 , A 2 = Count   of   { K 1 , ⋯ , K i − 1 } ∈ S 2</p><p>B 1 = Count   of   { ⋯ , H i − 1 } ∈ S 1 , B 2 = Count   of   { ⋯ , H i − 1 } ∈ S 2 ,</p><p>B 3 = Count   of   { ⋯ , H i − 1 } ∈ S 3</p><p>→ A 1 = B 1 , A 2 = B 2 + B 3</p><p>K i + 1 ∈ S 1 → H i + 1 ∈ S 1 → D i + 1 = A 2 = i − A 1 = i − B 1 = B 2 + B 3 = E i + 1 <sub> </sub></p><p>→ The invariant factors match the definition</p><p>K i + 1 ∈ S 2 , H i + 1 ∈ S 2 → definition&#160;of&#160; H ( L 2 , L 3 , V ) E i = D i + B 3 = − A 1 + B 3 = − B 1 + B 3</p><p>→ definitionof H ( N , L 2 , L 3 , V ) Match the definition</p><p>K i + 1 ∈ S 2 , H i + 1 ∈ S 3 → definition&#160;of&#160; H ( L 2 , L 3 , V ) E i = D i – B 2 = − A 1 − B 2 = − B 1 − B 2</p><p>→ definitionof H ( N , L 2 , L 3 , V ) Match the definition</p><p>→ Match the definition of H ( N 1 , N 2 , N 3 , K ) → recursion ⋯</p><p>q.e.d.</p><p>Example 3.2 { K 1 , K 2 , K 3 } = { A , B , C }</p><p>H ( 1 , 2 , K ) = A ( B − 1 ) ( C − 1 ) + A ( B + 1 ) ( C − 1 ) + A B ( C + 2 ) = 3 A B C</p><p>A ( B − 1 ) ( C − 1 ) ∈ S 1 S 2 S 2 → { F } = { A } → A { ( B − 1 ) ( C − 2 ) + ( B − 1 ) C }</p><p>→ A ( B − 1 ) ( C − 2 ) + A ( B − 1 ) C ∈ S 1 S 2 S 3 + S 1 S 3 S 2</p><p>A ( B + 1 ) ( C − 1 ) ∈ S 2 S 1 S 2 → { F } = { B + 1 } → ( B + 1 ) { A ( C − 2 ) + A C }</p><p>→ A ( B + 1 ) ( C − 2 ) + A ( B + 1 ) C ∈ S 2 S 1 S 3 + S 3 S 1 S 2 <sub> </sub></p><p>A B ( C + 2 ) ∈ S 2 S 2 S 1 → { F } = { C + 2 } → ( C + 2 ) { A ( B − 1 ) + A ( B + 1 ) }</p><p>→ A ( B − 1 ) ( C + 2 ) + A ( B + 1 ) ( C + 2 ) ∈ S 2 S 3 S 1 + S 3 S 2 S 1</p><p>H ( 2 , 1 , K ) = A B ( C − 2 ) + A ( B + 1 ) ( C + 1 ) + A ( B − 1 ) ( C + 1 ) = 3 A B C</p><p>A B ( C − 2 ) ∈ S 1 S 1 S 2 → { F } = { C − 2 } → ( C − 2 ) { A ( B − 1 ) + A ( B + 1 ) }</p><p>→ A ( B − 1 ) ( C − 2 ) + A ( B + 1 ) ( C − 2 ) ∈ S 1 S 2 S 3 + S 2 S 1 S 3</p><p>A ( B + 1 ) ( C + 1 ) ∈ S 2 S 1 S 1 → { F } = { A } → A { ( B + 1 ) C + ( B + 1 ) ( C + 2 ) }</p><p>→ A ( B + 1 ) C + A ( B + 1 ) ( C + 2 ) ∈ S 3 S 1 S 2 + S 3 S 2 S 1</p><p>A ( B − 1 ) ( C + 1 ) ∈ S 1 S 2 S 1 → { F } = { B − 1 } → ( B − 1 ) { A C + A ( C + 2 ) }</p><p>→ A ( B − 1 ) C + A ( B − 1 ) ( C + 2 ) ∈ S 1 S 3 S 2 + S 2 S 3 S 1</p><p>H ( 1 , 1 , 1 , K ) = A ( B − 1 ) ( C − 2 ) + A ( B − 1 ) C + A ( B + 1 ) ( C − 2 )     + A ( B + 1 ) C + A ( B − 1 ) ( C + 2 ) + A ( B + 1 ) ( C + 2 ) = 6 A B C</p><p>3.1) ( K 1 , K 2 , ⋯ , K M ) is permutable in H ( N 1 , N 2 , ⋯ , N q , K , S )</p><p>3.2) H ( N 1 , N 2 , ⋯ , N q , K , S ) = ∏ i = 1 M ( K i + D i )</p><p>→ H ( N q , N q − 1 , ⋯ , N 1 , K , S ) = ∏ i = 1 M ( K i − D i )</p><p>3.3) In the section 2, S U M ( N , P Y ) = ∑ A i ( P M i )</p><p>A i is generated by the form ( G 1 + K 1 ) ( G 2 + K 2 ) ⋯ ( G M + K M ) . It can be understood asgenerated by 2-SET: { G i } , { K i } .</p><p>If K i = J 1 , i + J 2 , i + ⋯ + J x , i , ( J x , i &gt; 0 , J x , i = 0 , J x , i &lt; 0 are allowed),</p><p>S U M ( N , P Y ) = ∑ B i ( P M i )</p><p>B i can be understood asgenerated by (X + 1)-SET: { G i } , { J 1 } , { J 2 } , ⋯ , { J X }</p><p>3.4) K i = J 1 , i + J 2 , i + ⋯ + J x , i , Theorem 2.3 has the similar promotion.</p><p>4. Conclusion</p><p>Review the whole process, ( N M ) + ( N M + 1 ) = ( N + 1 M + 1 ) → Basic Shapes in [<xref ref-type="bibr" rid="scirp.103005-ref1">1</xref>] → More Shapes in this article.</p></sec></sec><sec id="s3"><title>Conflicts of Interest</title><p>The author declares no conflicts of interest regarding the publication of this paper.</p></sec><sec id="s4"><title>Acknowledgements</title><p>The author is very grateful to Mr. HanSan Z. (Department of Electronic Information, Nanjing University) for his suggestions on this paper.</p></sec><sec id="s5"><title>Cite this paper</title><p>Peng, J. (2020) Subdivide the Shape of Numbers and a Theorem of Ring. Open Access Library Journal, 7: e6719. https://doi.org/10.4236/oalib.1106719</p></sec></body><back><ref-list><title>References</title><ref id="scirp.103005-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">Peng, J. (2020) Shape of Numbers and Calculation Formula of Stirling Numbers. Open Access Library Journal, 7: e6081. https://doi.org/10.4236/oalib.1106081</mixed-citation></ref></ref-list></back></article>