AN ABSTRACT OF THE THESIS OF Santiago Sologuren P. Science Title: Mathematics in Master of for the degree of presented on December 16, 1982 Systems of Incongruences in a Proof on Addition mod m. Abstract approved: Redacted for Privacy Robert D. Slitalley Let N = N(k,m), that for any sequence of length k m and k are positive be the smallest positive integer so k < m, integers, where N containing at least integers which are distinct mod m sequence with zero sum there exists a sub- mod m. A result that we call the Fundamental Theorem states: If m=11,13,16,17, or m > 19, then N(4,m)<m-6. We obtain a set of 61 systems of incongruences any one of which may lead to a variation of the proof of the Fundamental Theorem. Also, such a new proof may supply us with a method for obtaining corresponding results for N(k,m), where k > 5. A relationship is explored between the above systems of incongruences and a collection of families of subsets of the set {a,b,c,d}. SYSTEMS OF INCONGRUENCES IN A PROOF ON ADDITION mod m by Santiago Sologuren P. A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Completed December 16, 1982 Commencement June, 1983 APPROVED: Redacted for Privacy Professor of Mathematiin charge of major Redacted for Privacy Chairman of Department of Mathematics Redacted for Privacy Dean of Grate School Date thesis is presented December 16, 1982 Typed by Jolan Eross for Santiago Sologuren P. Acknowledgments I wish to express my gratitude to my major professor, Dr. Robert D. Stalley, a man of highly noble human qualities, who has contributed a great deal to my intellectual formation. I also thank my friend, Jolin Eross who typed this thesis in a very professional manner. Table of Contents Page Introduction 1 Chapter I. Fundamental Theorem and Preview Chapter II. An Analysis Yielding Representatives . of Eighteen S-10 Families Chapter III. 10 Representatives of All Equivalence Classes of S-10 Families Chapter IV. 4 23 Representatives of All Equivalence Classes of S-10 Systems 30 Epilogue 58 Bibliography 59 List of Tables Page Table I. Some values of N(k,m) mainly for k < 4 2 Table II. S-10 Families Table III. S-10 Systems of Given Table IV.. S-10 Families of Given S-10 Systems. Table V. Incongruences of Standard Repre- 24 S-10 Families sentatives Table VI. 33 36 40 S-10 Systems in Each Part of Rank Two With More Than One S-10 System. 56 SYSTEMS OF INCONGRUENCES IN A PROOF ON ADDITION mod m Introduction In this thesis we are concerned with an aspect of the problem of determining how long a sequence of integers mod m must be in order that there will necessarily exist a subsequence with zero sum mod m given a lower bound on the number of integers in the sequence that are pairwise distinct mod m. Let us be more precise. integers where k < m. Let Let k N = N(k,m) and m be positive be the smallest positive integer such that for any sequence of length containing at least k N integers which are distinct mod m there exists a subsequence with zero sum mod m. Then, the problem is that of evaluating the number theoretic function N(k,m). where 1 < k < m. First, we list several known results, mainly for k < 4, in the following table. (1) 2 Table I. Some values of N(k,m) mainly for k < 4 N (k,m) (k,m) 2 k=1 1<k<m 3 m < 2k 4 k> 2; m> 1 5 6 7 8 9 10 11 12 in k<N<m k 1 2 k = 2; m = 2 k=2;m>3 k= 3 ; 3 >1. m > 5 k = 3; m = 6 k=3;m>7 k= 4; 4 <m< <8 .... k = 4; m = 9, 10 k=4; m=11, 13, 16, 1 2 N> m- k (k+1 ) 2 m-1 3 MM. 4 m-3 ..... 4 ..._ 5 17 or m>19 m- 6 k (k-1) 3 Entry 12 follows from entry 4 together with the following theorem that will be called the Fundamental Theorem. This theorem is the deepest of the known results for N(k,m). Fundamental Theorem. m > 19, then N(4,m) If m = 11, 13, 16, 17, or < m-6. In this thesis we list a set of systems of incongruences each system of which may lead to a variation of the proof of the Fundamental Theorem. In Chapter I we give a part of the proof of the Fundamental Theorem which serves to motivate the reminder of this thesis. We show that our proof of this theorem is based on one of the above mentioned systems of incongruences mod m. Furthermore, we include a description of the contents of Chapters II, III and IV. In the epilogue we discuss three related new problems to which one is lead by this research. 4 Chapter I Fundamental Theorem and Preview We will start by giving a partial proof of the Fundamental Theorem to motivate the thesis, then we introduce in an informal but more detailed fashion than in the introduction the problem of the thesis. Throughout the present work congruences are understood to have modulus m. We restate the Theorem. Fundamental Theorem. m > 19, then N(4,m) If m = 11, 13, 16, 17, or < m-6. Partial proof (1) . Let and suppose that the sequence m=11, 13, 16, 17, or m > 19, Q = {al, a2, ... a m-6} of m-6 integers contains at least four integers which are distinct mod m. with zero sum We show that Q contains a subsequence mod m. We assume that no subsequence of Let distinct m-9 has a zero sum and obtain a contradiction. mod m, a Q a, b, c mod m. = a, a m-8 and d be elements of Q which are Suppose, without loss of generality, that = b a ' m-7 Consider the sums = c, and a m-6 = d. 5 s 1 = a1 s2 = al + a = a 2 + a s m-10 s m-9 = a 1 + a 2 s m-8 s m-7 s m-6 s m-4 s m-3 s m-2 s = a = a = a m-5 s s = a = a = a = a = a m-1 = a m 1 + a 1 1 1 1 1 + a + a + a + a + a 1 1 1 + a + a 1 + a 2 2 2 2 + + a + + a m-10 + a + + a + + a + + a + + a + + a + + a + + a + + a + + a 2 2 2 2 2 2 m-10 m-10 m-10 m-10 m-10 m-10 + b + c + d + a+b + c+d m-10 + a+b+c m-10 m-10 m-10 + a+b+d + a+c+d + a+b+c+d First, we establish conditions under which these sums are distinct m mod m. In this case, since there are of these sums, one of them is zero mod m, which is a contradiction. If 1 < i < j < m, and i < m-10. then s, - s J isthesumofasubsequenceofQ,andso,, 1 J thatis,s,J ts.1 .fience, it suffices to consider the sums where m-9 < i < j < m. 6 Thus, it suffices to consider the sums: a b d a+b c+d a+b+c a+b+d a+c+d a+b+c+d. Since and a,b,c, d are distinct the sum of the elements of any subset of not zero mod m, mod m {a,b,c,d} and is by inspection, the conditions reduce to a+b+c t d a+b+d t c a+c+d t b a+b c+d a+b c a+b t d c+d t a c+d t b We consider the {a,b,c,d}, 4: = 24 permutations of the set and observe that we can replace the above sys- tems of incongruences by any of the 24 transformed systems of incongruences. Notice that the above system of incongruences is invariant under the permutation (c,d). Thus, 24 transformed systems can be paired off into 12 pairs of identical systems. 7 If any of the 12 systems of incongruences hold we The other case to consider is where have a contradiction. That is, for each of the 12 systems all 12 systems fail. one incongruence is replaced by a congruence, and these congruences are taken simultaneously. Every such system (1) of congruences can be shown to lead to a contradiction. Let S = {a,b,c,d }. An S-10 family is a set of 10 nonempty subsets of S which includes the set S. It may happen that variations of the proof of the Fundamental Theorem can be based on different choises of an S-10 family than made in the above partial proof. As in the above partial proof of the Fundamental Theorem we impose the restriction that no two subsets in the family have sums that are congruent For this reason we are mod m. interested in identifying all S-10 The reason we define an set S-10 families. family to include the is that otherwise the proof of the Fundamental Theo- S rem would be unnecessarily longer, more precisely, it would contain all of the steps of the proof based on an family, and also some other additional steps. S-10 To show this, consider any family that is defined in the same way as an S-10 family, but where the set element. S is not included as an The collection of incongruences of the system corresponding to such a family is a super-collection of the collection of incongruences of the system corresponding to 8 S-10 some family. Thus we may take the S-10 family which is formed by replacing one of the proper subsets of S by Hence, the collection of systems of congruences S. corresponding to the system of incongruences is a supercollection of the collection of systems of congruences corresponding to the S-10 system. Next, we calculate the number of Since an S-10 family contains the set S-10 families. S, the remaining 9 elements must be chosen from the 14 proper non-empty subsets of is S. The number of ways in which this can be done 95: = 2,002. Two S-10 families are equivalent if one can be transformed into the other by a permutation on the set S. Therefore, variations of the proof of the Fundamental Theorem that are based on equivalent tical except for the notation. S-10 families are iden- Hence, we restrict our at- tention to a complete system of representatives from our equivalence classes of S-10 families. In Chapters II and III we develop a list of representatives of these equivalence classes. There are 122 of them. Two systems of incongruences which correspond to S-10 families are equivalent if one can be transformed into the other by a permutation on the set S. The variations to which we have been referring of the proof of the Fundamental Theorem are based on the 9 several systems of congruences that are yielded from one of the systems of incongruences corresponding to an S-10 family as in our partial proof of the Fundamental Theorem. It may happen that a system of incongruences does not lead in this manner to a proof of the Fundamental Theorem. (2) On the other hand, equivalent systems of incongruences, except for notation, lead to the same proof, while nonequivalent systems of incongruences may or may not lead to the same proof. For this reason we consider a complete set of representatives from the equivalence classes of the above systems of incongruences. In Chapter IV we develop a list of representatives of such equivalence classes. is interesting that there are 61 of them. It 10 Chapter II An Analysis Yielding Representatives of Eighteen S-10 Families Before stating the contents of Chapter II we give three definitions. We continue to let Definition 1. empty subsets of S An S-10 . family is a set of 10 non- which contains the universe Definition 2. an S-10 S = {a,b,c,d} S. A subfamily (of S) is a subset of family. Definition 3. Two subfamilies (of S) are equi- valent when one subfamily is transformed into the other under a permutation on S. In this chapter we include a thorough analysis yielding representatives of all equivalence classes of S-10 families which contain all four singletons. There are 18 of these equivalence classes. Before we go any further we give two more definitions. Definition 4. A singleton, a double, a triple and a quadruple is a subset of four elements of S Definition 5. S of one, two, three, and respectively. A (u-v) subfamily (of S) is a subfamily that contains u triples and v doubles. 11 Since u+v = 5 we have five cases. need to find only the In each case we (u-v) subfamily since then the S-10 family is completely determined. Case 1 (Four triples and one double.) Consider the subfamilies: = { {a,b,c }, -5 1 {a,b,d }, {a,c,d }, {b,c,d } }, = {{a,b} 1, and U .a 3 Theorem 1. valent to family Proof. S. Thus, double of Any (4-1) subfamily of 31. Let 3 be an arbitrary (4-1) subfamily of 3 = 7 U .5, S. where Then, a, y b. is an arbitrary .5 = {x,17} is equivalent to the following permutation on x is equi- S S transforms (The other elements of S 31 because into 3 31: are fixed under the permutation.) Case 2. (Three triples and two doubles). Consider the subfamilies: 3 = {{a,b,c}, 13' 1 5 -13' -& 2 3 4 {a,b,d }, = {{a,b}, {a,c } }, = { {b,c }, {b,d} }, = { {a,b }, {b,c } }, { {a,b }, {c,d}}, = {a,c,d}}, and 31 = U l' 3 2 = 7 U .6 2' 3 =3U.} 3 U 4 4' 12 Any (3-2) subfamily of Part (a). Theorem 2. is equivalent to one of the subfamilies 31, 32, 33 S and 3 Subfamilies Part (b). and 1 , 32' are not equivalent to each other. 3 4 Proof of Part (a). subfamily of z, and 3 be an arbitrary (3-2) as follows: 3 {{a,b,c}, {a,b,d }, {a,c,d}} {{a,b,c}, {a,b,d}, {b,c,d}} {{a,b,c}, {a,c,d}, {b,c,d}} {{a,b,d}, {a,c,d}, {b,c,d}} . be the element of this singleton, and x w 3 This is clear by considering all possible collections of triples in Let Let The intersection of the triples in S. is a singleton. y, 3 be the remaining elements of S. The subfamilies are classified into four types. doubles. Type 1. (The element Let and y be the other elements in these Hence, the doubles are Type 2. Let doubles. z is in each double.) x y (The element x {x,z}. is in neither double.) be the element which is common to both Hence, the doubles are Type 3. {x,y}, (The element x {y,z}, {y,w }. is in just one double and the intersection of the two doubles is nonempty.) 13 Let be this intersection, and let y other element of the second double. are {x,y }, be the z Hence, the doubles {y,z }. Type 4. (The element is in just one double x and the intersection of the two doubles is empty.) Let y be the other element in the first double. {x,y }, Hence, the doubles are {z,w }. Suppose that a subfamily is equivalent to subfamily 31, 3 permutation on z -0- then c, 3 3 into 31: Similarly, if 0 is of type 2, 3 1' a, 3 y+ or b, 4, or 34 This completes the proof of Part (a). Proof of Part (b). families x -4- is equivalent to subfamilies 32, 33, respectively. Then, because the following transforms S w -0- d. is of type 1. 3 3 2' 3 and 3' is a permutation on 3 4 are equivalent. Subfamily 3j, 3i i+j, transformed into Then there transforming one of these sub- S families into the other. into subfamily Assume that two of the sub- is transformed only if .&j. is Notice that the intersection of the 3 doubles in 51,.52,.83 {b}, and .54 is the singleton and the empty set respectively. forming &i. into .6j {a}, {b}, A permutation trans- 1<i<4, 1<j<4, i+j, transforms the intersection of the doubles in Si into the intersection of the doubles in 3 is not equivalent to Hence, 3 4 14 either or 31, 1 doubles in .5 doubles in 5 3 is empty and the intersections of the and 11 32 equivalent to either transformed into into 31 32 since the intersection of the 3 or 3 are not. .5 3 or 2 3 Also, 3 is not 1 since otherwise 3 {a} is {b} under the permutation transforming 33. But, since the intersection of the triples in the subfamily is j {a }, u is trans- 32 since the then formed into a different subfamily of triples. Finally, element a is not equivalent to 33 appears in one of the doubles of 33 neither of the doubles of tion transforming b, c or d. .53 .52. into But then q That is, for any permuta- 32 the image of a. must be is transformed into a different subfamily of triples. Case 3. (Two triples and three doubles.) Consider the subfamilies, = { {a,b,c }, {a,c }, {b,c }} = { {a,b }, {arc}, {a,d } }, = { {a,b }, {a,c}, {b,d } }, = { {a,c }, {a,d }, {c,d}} 3 5 = {{a,c}, 36 = {b,c}, {c,d}} {b,d}, {c,d }} 3 = {{a,b}, {a,c}, {c,d}} = { {a,c }, {a,d }, {b,c } }, .5 .5 = 2 3 .5 4 7 38 and {a,b,d} 1, { {a,b }, 1 but in 15 2, 31 7U '&1' 32 35 = 51j.,5 36 = a U .56, 5, Theorem 3. U Part (a). S 33 37 = 7 U 36, 37 and f 3 8 Any (2-3) subfamily of 3 5' 6' 3 7 and 3 8 S, 34, Subfamilies 31, 32. 33' 34' are not equivalent to each other. Proof of Part (a). subfamily of 33, 32, 31, S . Part (b). 3 38 = .19-71 is equivalent to one of the subfamilies 35 , 7U 34 U and let Let be an arbitrary (2-3) 3 and {x,y}, be the inter- {z,w} section and its complement respectively of the two triples. The subfamilies are classified into 8 types. Type 1. (fx,y1 is one of the doubles, {z,w} is not, and the intersection of the other two doubles is a singleton not in the first double.) Let the intersection be x. Then and x the other elements in these remaining doubles. doubles are {x,y }, {x,z }, Type 2. (fx,y1 and y are Hence, the {y,z}. is one of the doubles, and the intersection of the other two doubles is a singleton in this double.) Note that fz,w1 Let this intersection be is not one of the doubles.) x. Then z and the other elements in these remaining two doubles. w are Hence, 16 the doubles are Type 3. {x,y }, ({x,y} {x,z}, and fx,w1. is one of the doubles, and the Note intersection of the other two doubles is empty.) that is not one of the doubles. {z,w} One of the elements of one of these other two doubles is z. x. Let the other element of this double in Hence, the doubles are Type 4. ({z,w} {x,y}, {x,z}, and {y,w}. is one of the doubles, {x,y} is not, and the intersection of the other two doubles is a singleton not in the first double.) Let this intersection be x. Then z and w the other elements in these remaining two doubles. the doubles are Type 5. {x,z}, {x,w }, ({z,w} and are Hence, {z,w }. is one of the doubles, and the intersection of the other two doubles is a singleton in Note that this double.) {x,y} is not one of these doubles. Let this intersection be z. Then x and the other elements in these remaining two doubles. the doubles are Type 6. {x,z}, {y,z}, ( {z,w} and {x,y} are Hence, {z,w }. is one of the doubles, and the intersection of the other two doubles is empty.) that y Note is not one of these doubles. One of the elements of one of these other doubles 17 in Let the other element of this double be z. Hence, the doubles are Type 7. {x,z}, {y,w}, and ({x,y} and x. {z,w}. are two of the {z,w} doubles.) The remaining double must contain an element of say {x,y}, and an element of x, Hence, these doubles are Type 8. {x,y}, {x,z}, (Neither nor {x,y} element of each of the doubles and permutation in S y w c, -0- 3 3 or y is an be the other {x,z}, 3 is of Type 1, then because the following into 3 3 1 x 31: a, d. is of Type 2, 3, 4, 5, 6, 7, or 3 32, 33, 34, 35, respectively. 8 Proof of Part (b). families z is equivalent to subfamily 8, then 7' 3 31 transforms Similarly, if 3 Then Thus, {y,z}. 3 is equivalent to subfamily 6' {z,w}. Hence, the doubles are Suppose that a subfamily z and {x,y} are these doubles. {x,w} element of this double. b, are one of {z,w} element of the third double, and let {x,w} {z,w}. is an element in two of the doubles. x and {x,z} and z. Each of the three doubles must contain an the doubles.) Suppose say {z,w}, 2 , 3 3' 3 4 , Assume that two of the sub3 5' 3 6 and 3 7 , 3 8 are 18 Let equivalent. be a permutation on p Subfamily 3i one of these subfamilies into the other. is transformed into subfamily only if Pi 3 is transformed into Notice that and { a,b} 1<i<8, , transforming S 1<j<8, i+j, p.j. are the intersec- {c,d} tion and its complement respectively of the triples in . Thus, the doubles under P. {a,b} and 34. a5, .56 families Hence, since 3 1' 3 3 1' 3 2' 3 of the subfamilies since 3-7 subfamily and and {a,b} 3 contains 37 33 and 38 and 3 2' 4' 3 3 5' {c,d} and ,5 contain 7 do not, each of the sub- is not equivalent to each 7 3 are invariant { c,d} and 6' and 3 Similarly, 8. ,al, .52 and 33 do not, is not equivalent to subfamilies 32' 33. The double and 33. 31, .52, {a,b} is an element of the subfamilies The intersections of the remaining two doubles in these subfamilies is the singleton and the empty set respectively. ing 3i into 3j, 1<i<3, {c}, {a}, A permutation transform- 1<j<3, transforms the i+j, intersectionofthesecondandthirddoublesin3.into the intersection of the second and third doubles in Hence, since the image of element or then d, 31 is not equivalent to since the image of element then 3 2 c a is not equivalent to must be either 32 and must be either 33. 33. a or 3.. c Also, b, 19 By an argument similar to the one in the last paragraph, since the double families and J.54, belongs to the sub- {c,d} 9-6, and the intersections of the remaining doubles in these subfamilies are and the empty set respectively, 35 and and 36, 35 {c,d}, is not equivalent to is not equivalent to Since the subfamily P8 or 34 {a}, {c }, 36. does not contain {a,b} and is the only subfamily of doubles with this property, is not equivalent to any of the re- 38 maining seven subfamilies, in particular subfamilies 34, 35, and 36. Case 4. (One triple and four doubles.) Consider the subfamilies: = { {a,b,c } }, $1 = {{a,d}, {a,b}, {a,c}, {b,c}}, = {{a,d}, {b,d}, {c,d}, {a,b}1, = {{a,d}, {b,d }, {a,b}, {a,c} }, = {{a,d}, {b,d}, {a,c }, {b,c}}, 13' .6 2 3 and 31 =JUP 1 Theorem 4. 3 2 =JU.i5 2 Part (a). 3 3 = 7U 34 = 4 3' Any (1-4) subfamily of is equivalent to one of the subfamilies 31, 32, 33 34. Part (b). and 3 4 Subfamilies are not equivalent to each other. , 32, 33 U,54. 4 S and 20 Proof of Part (a). subfamily of S, and let in the triple. of Let Let y, x z, be an arbitrary (1-4) 3 be the element which is not and w be the other elements S. The subfamilies are classified into 4 types. Type 1. Let (The element x is in one double.) be the other element of this double. y the remaining doubles are formed by {y,x }, Hence, the doubles are y, z, {y,z}, and {yew }, Then, w. and fz,wl. Type 2. Then (The element y, z, and w y and x is in three doubles.) are the other elements in these doubles. Let fourth double. Hence, the doubles are be the elements in the z {y,x }, {z,x }, {y,z}. {w,x}, Type 3. (The element x is in two doubles and the other two elements of these doubles form another double.) Let and y z be these other two elements, and belong to the remaining double. let y are {y,x }, {z,x }, Type 4. {17,z}, (The element and x Hence, the doubles {y,w }. is in two doubles and the other two elements of these doubles do not form another double.) 21 Let y and y be these other two elements. z Thus, belongs to one of the doubles that does not contain and belongs to the other double that does not contain z Hence, the doubles are x. {y,x}, {z,x }, and {y,w }, {z,w}. Suppose that a subfamily 3 is equivalent to subfamily 3 mutation on w 4 c, then transforms S is equivalent to 3 then because the following perinto 3 Similarly, if x 4 d. is of Type 1, z 4 b, is of Type 2, 3, or 4, 3 32, 3 y 4 a, 31: 3' or 3 4 respectively. Proof of Part (b). families 31, 32, 33, be a permutation on and then 7, Subfamily 1<i<4, 1<j<4, Thus, since of J5 3 3i i+j Since d leaves P d is transformed into subfamily only if .9-i not equivalent to either 32, 33, not equivalent to either 33 which contain doubles in 3A d are p invariant. {a,d} which contain or and d. 3j. is transformed into and three doubles of 4' Let does not belong to the appears in one double of d and are equivalent. 34 transforming one of these sub- S families into the other. triple of Assume that two of the sub- or 34. two doubles 0-1, 2' 34, then and 3 32 The doubles of {b,d }, is 1 is 3 the same Thus, any permutation 3 22 However, 33 into 33 transforming belongs to {a,b} is not equivalent to {a,b} leaves 34 .B.3, but not to invariant. Hence, .(94. 34. (No triple and 5 doubles.) Case 5. Consider the subfamilies: 1 = { {a,b }, {a,d}, {a,c}, {b,d}}, {b,c}, and Theorem 5. Any (0-5) subfamily of valent to subfamily Proof. be any subfamily of fine doubles. 3 There are altogether 3 is equi- 31. Let one double not in S Let 3. is equivalent to 31 doubles, and so there is = 6 (2) be this double. {x,y} Then, because the following permutation x y transforms 3 into other elements of S are fixed under the permutation.) on S 3 : 1 c, d. (The 23 Chapter III Representatives of All Equivalence Class of S-10 Families. In this chapter we give Table II which lists the subsets of class of S in a representative of each equivalence S-10 The representatives of equi- families. valence classes of families which contain fewer S-10 than four singletons can be obtained by an analysis similar to that in Chapter II. We first explain how to read Table II. The main headings are the singletons, the first subheadings are the triples, and the second subheadings are the doubles of an family. S-10 Since the set is common to all S S-10 families it has been omitted from the table. To the left of the doubles of an appears a symbol .0 i , where 1<i<122 S-10 family that denotes the family. For instance, {c,d} d3,5 consists of the doubles in the second subheading, the triples {a,b,d}, {a}, {b}, that i05 {a,c,d} {c}, {a,b}, {a b,c}, in the first subheading, and the singles and denotes the {d} S-10 in the main heading. (Note family that was used in Chapter I in the partial proof of the Fundamental Theorem.) 24 Table II S-10 Families {c}, {d} {a }, . {a,b,c}, {a,b,d }, {a,c,d }, {b,c,d} {a,b} 1 {a,b,c}, {a,b,d }, {a,c,d} {a,b }, {a,c} 2 {b,c }, {b,d} 3 {a,b }, {b,c} 43,4 {a,b}, {c,d} 5 {a,b,c }, {a,b }, {a,c }, {b,c} 6 {a,b }, {a,c}, {a,d} 7 {a,b}, {a,c }, {b,d} {a,c }, {a,d }, {c,d} 9 m10 {a,c }, {b,c }, {c,d} 11 {a,c }, {b,d }, {c,d} $12 {a,b }, {a,c }, {c,d} {a,c }, {a,d }, {b,c} 1 3 {a,b,c} S14 {a,d }, {a,b }, {a,c }, {b,c} .0 15 {a,d }, {b,d }, {c,d}, {a,b} .4016 {a,d }, {b,d }, {a,b }, {a,c} .0 17 {a,d }, {b,d }, {a,c }, {b,c} 18 {a,b }, {a,c }, {a,d }, {b,c }, {b }, {b,d} {c}, {d} {a,b c}, {a,b,d }, {a,c,d }, {b,c,d} 25 Table II (continued) 4 19 4 20 4 21 4 22 {a,b}, {a,c} {a,b }, {b,c} {a,b}, {c,d} {b,c}, {c,d} {a,c,d} {a,b,c}, 423 4 25 26 27 4 28 {a,c}, {a,d} {a,b }, {a,c}, {b,c} {a,b }, {a,b}, {a,c}, {b,d} {a,b }, {b,c}, {a,b }, {b,c }, {c,d} {b,d} {b,d}, {c,d} {b,c}, {a,b,d}, {a,c,d}, {b,c,d} {a,b}, {a,c}, {b,c} {b,d }, {b,c} {a,b}, {b,c}, {c,d} .;,32 {a,b }, {b,c}, {b,d} 433 {a,b}, {a,c}, {b,d} {a,b }, {c,d} 435 {a,d}, {a,b}, {a,c} 436 437 {a,d}, {a,b}, {b,c} {a,d}, {c,d} 438 {a,d}, {b,c}, {c,d} .9 30 31 .134 {a,b,c }, {a,b,d} 439 440 {a,b}, {a,c}, {aid}, {c,d} {a,b}, {b,c }, {a,c}, {a,d} 4 41 {a,b}, {b,c}, {a,c }, {c,d} {a,b}, {b,c}, {c,d} 42 {a,d}, 26 Table II (continued) 43 JJ 44 45 46 24 47 {ado}, {b,c}, {b,d}, {a,c} {a,b}, {b,c}, {b,d}, {b,c}, {a,c}, {a,d}, {c,d} {c,d} {b,c}, {b,d}, {a,c}, {a,d} {b,c }, {b,d}, {a,c}, {c,d} {a,b}, {a,c}, {a,d}, {c,d} {a,b}, {a,c}, {b,c}, {a,d} {ado}, {a,c}, {b,c}, {c,d} {a,c,d}, {b,c,d} 48 49 $50 {b,c}, 5l di, 4;, do 53 54 56 {c,d} {a,c} {a,b }, {b,c }, 52 55 .;v' {a,d}, {ado}, {b,c}, {b,d}, {c,d} {a,c}, {a,d}, {b,c}, {c,d} {a,c}, {a,d }, {b,c}, {b,d }. {b,c}, {b,d}, {a,c}, {c,d} {a,b}, {a,c }, {a,d}, {b,c}, {a,c}, {a,d }, {b,c }, {a,b }, {a,c}, {a,d}, {b,d}, {c,d} {a,c }, {a,d}, {b,c}, {b,d}, {c,d} {a,b}, {a,c}, {a,d}, {b,c}, {b,d} {b,c}, {b,d }, {c,d} {a,b}, {a,c}, {a,d }, {b,c}, {b,d}, {c,d} {b,c,d} 57 58 59 60 61 {a,b }, {a,c}, 62 {b,d} {c,d} No triple. 63 {c}, {d} {a,b,c}, {a,c,d }, {b,c,d} 27 Table II (continued) 64 65 66 67 S69 ..!) 71 {a,b }, {a,c}, {b,c} {a,b}, {a,c}, {a,d} {a,b}, {a,c}, {b,d} {a,b }, fa,c1, {c,d} {a,c}, {b,c}, {c,d} {a,c}, {a,d}, {c,d} fa,c1, {b, d }, {c,d} {a,c}, {a,d}, {b,c} {a,b,c}, {a,b,d }, {a,c,d} S72 {a,b}, {a,c}, {a,d }, S73 {a,b }, {b,c}, {a,c }, S74 {a,b }, {b,c}, {a,c}, {cad} {a,b}, {b,c}, {a,d}, {c,d} S76 {a,b}, {b,c}, {b,d }, S77 {a,b}, {b,c}, {b,d}, {c,d} S78 {b,c }, {a,c}, {b,c}, {b,d}, {a,d}, {c,d} {a,c}, {a,d} {b,c}, {b,d}, {a,c }, 75 79 80 {a,b,d}, {a,c,d }, {c,d} {a,d} {a,c} {c,d} {b,c,d} {a,b}, {a,c }, {b,c}, {c,d} S82 {a,b}, {a, c }, {aid}, {c,d} S83 {a,b}, {a, d }, {b,c}, {c,d} {a,b}, {a, d }, {b,d}, {c,d} {a,b}, {a, c }, {a,d}, {b,c} {a,b}, {a,c}, {a,d}, {b,d} {a,c}, {a,d}, {b,c}, {c,d} {a,c}, {a,d}, {b,d}, {c,d} {a, c }, {a,d }, {b,c}, {b,d} 81 84 S 85 86 "87 S 88 89 {a,b,c}, {a,b,d} 90 {a,b}, {a,c }, {a,d}, {b,c}, {b,d} {b,d}, {c,d} :Y91 {a,c}, {a,d}, {b,c}, S92 {a,b}, {a,d }, {b,c}, {c,d} 28 Table II (continued) {a,b,d }, {b,c,d} .3( S 93 94 95 {a,b }, {a,c }, {a,d }, {b,c }, tb,d} {aic}, {a,d}, {b,c }, {b,d }, {c,d} {a,b}, {a,d }, {b,c }, {b,d }, {c,d} {a,b,c }, {a,c,d} 96 S 97 {a,b }, {a,c }, {a,d }, {b,c }, {b,d} {a,b}, {a,c }, {a,d }, {a,b }, {a,c }, S 99 100 5101 {b,c}, {c,d} {a,d }, {b,d }, {c,d} {a,b }, {a,c }, {b,c }, {b,d }, {c,d} {a,b}, {a,d }, {b,c}, {b,d }, {c,d} {c,d} .{a,c}, {a,d}, {b,c }, {b,c,d} I./ 102 {a,b }, {a,c }, {a,d }, {b,c }, {b,d }, {c,d} {a,b,c} S 103 {a,b }, {a,c }, {a,d }, {b,c }, {b,d }, {c,d} {a,b,c }, {a,b,d }, {a,c,d }, {b,c,d} 104 S 105 S 106 S 107 {a,b }, {a,d }, {b,d }, {b,d }, {c,d} {c,d} fa,b1, {a,c }, {a,b }, {a,c }, {a,d }, {b,d} {a,b }, {a,c }, {b,c }, {a,d} {a,b,c }, {a,c,d }, {b,c,d} 5108 109 {a,c }, {a,d }, {b,c }, {b,d }, {c,d} {a,b }, {a,c }, {bic}, {b,d }, {c,d} {a,b,c }, {a,b,d }, {a,c,d} S110 {a,c }, {a,d }, {b,c }, {b,d }, {c,d} 29 Table II (continued) ; ; 111 112 113 {c,d} {ab}, {a,c }, {b,c }, {a,b}, {a,c}, {a,d}, {b,d }, {a,b}, {a,c}, {a,d}, {b,c}, {b,d} {b,d}, {c,d} {a,b,c}, {a,b,d} ; 114 {a,b }, {a,c}, {a,c,d }, ; 115 {a,d }, {b,c }, {b,d}, {c,d} {a,d }, {b,c}, {b,d }, {c,d} {b,c,d} {a,b }, {a,c}, No singleton {a,b,c}, {a,b,d}, {a,c,d}, {b,c,d} ;116 {a,b}, {a,c}, {a,d}, {b,c}, {b,d} .bl17 {a,b}, {a,c}, {a,d}, {b,c}, {c,d} ;118 {a,b}, {a,c}, {a,d}, {b,d}, {c,d} {a,b}, {a,c}, {b,c}, {b,d}, {c,d} 119 ;120 {a,b}, {a,d}, {b,c}, {b,d}, {c,d} ii121 {a,c}, {a,d}, {b,c}, {b,d}, {c,d} {a,b,c}, {a,b,d}, {a,c,d} ;122 {a,b}, {a,c}, {a,d}, {b,c}, {b,d }, {c,d} 30 Chapter IV Representatives of All Equivalence Classes Systems S-10 of Before stating the contents of Chapter IV we give three definitions. Definition 6. An system of an S-10 S-10 family is the set of all incogruences obtained by setting the sums of the elements of every two members of the S-10 family incongruent to each other, cancelling common terms and discarding the resulting incongruences with zero on one side. Definition 7. Two subsystems of S-10 systems are equivalent if one can be transformed into the other by a permutation on S. If we transform the tem by a permutation on ing S-10 family of an S-10 S, the S-10 system of the result- family is identical to the system obtained from a transformation of the original permutation on S. Thus, an by a permutation on an S-10 S-10 sys- S S-10 S-10 into another system by the same system is transformed S-10 system. Given system, the equivalence class which contains this system consists of all transforms of this system under permutations on of the 2,002 S-10 S. Also, each of the S-10 systems families is a member of the equivalence 31 classes represented by families S-10 systems of one of the S-10 Hence, there are at most 122 of these equi- $i. valence classes. We will find out below that there are just 61 of them. Definition 8. The standard representative I. , 3 of the equivalence class of 1<j<61, systems which S-10 containstheS-10systerriof2iiisthesarsternI.of Table III, where the incongruences of are given in 3 Table V. In this chapter we show that the systems, I. 3 1<j<61, form a complete set of representatives of the equivalence classes of S-10 systems. First, we show that every valent to an I. system. S-10 system is equi- This is done in Table III. 3 Then,weshowthateveryl.3 system is an S-10 system. This is done using Table IV. Finallyfweshowthatnotwoofthel.3 are equivalent. systems This we do by listing them in Table V in such an order that is apparent that no two are equivalent. Now we explain how to read Table III. The in the first column, 1<i<122, represents anS-10fartlilyasgiverlinTableII.TheI. 3 second column, 1<j<61, denotes the standard in the 32 representative from the equivalence class of systems containing the S-10 system ofi. The symbol in the third column denotes the permutation on transforms the S-10 representative I.3 . S-10 system of S that into the standard Immediately following Table III is Table IV where we list the system I., 3 1<i<122, 1<j<61. corresponding to each 33 Table III S-10 Systems of Given S-10 Families Standard r epresentative 1 I1 2 17 I 3 4 1 4 6 I -3, 3 5 6 7 1 1 33 32 121 I 29 130 1 12 X13 14 15 16 S 17 18 1, S 19 20 I 13 I 1 I 1 1 49 47 48 36 58 4 6 Families Standard represeFamilies tative S -10 Permutation e e .'.21 e :Y22 17 (b,d) ,i,23 15 e I e (b,d) e ... 25 I 1 3 5 2 (c,d) (b,d,c) e 12 e e 15 e 15 e e S(28 e 128 (b,d) e .8,30 134 (a,b,d) e .8,31 119 (a,b,d) 131 (b,d) 114 (a,b) (c,d) 18 120 1 Permutation S-10 32 (c,d) (a,c) ..*34 126 (b,c,d) e .8,35 128 (a,b,c) 7S 112 (b,d) 134 (b,d) 125 (b,c,d) 115 e (a,b,c) 36 (a,c) (b,d,c) e e .* .,. 38 39 .;:*40 117 (c,d) 34 Table III (continued Standard represenFamilies tative 5 -I0 S 41 I S 42 I 43 I 22 8 Pe rmu- tation e (a,b) Standard S-10 r epresenFamilies tative Ji 61 S62 I 39 Permutation (a,c) 242 e 155 e 24 e S 44 227 e .4,64 (45 216 (c,d) S65 I29 (a,b) S I e $66 I13 e e .4,67 1 S 68 233 S 69 232 S70 I S 71 I S 46 47 48 S 49 .3, 50 ai51 S 52 53 .3, 54 S 55 .4, 56 I I I I 9 23 45 44 50 136 246 252 251 I 1 36 54 (a,c)(b,d) (b,d) 63 (a,c,b,d) (a,b,d) 72 (a,b,d,c) S73 (a,c). (b,d) (a,b,d) S 74 75 (b,d) (a,b,d,c) '776 ,:* 57 :4, 58 S59 I I 60 237 I 4°60 57 41 230 (a,d,b) (a,c,d) e (a,b,c) 77 18 21 20 (c,d) (a,b) (c,d) (c,d) (a,b) e (a,b) 227 e 223 (c,d) 222 (c,d) 1 1 I 8 16 15 S 78 I S 79 1 s 80 217 24 9 (a,b) e e (c,d) e e 35 Table III (continued S-10 Familie .b 81 82 83 84 85 86 87 ji 88 89 ,L4 90 91 92 93 94 95 96 97 98 99 100 101 s Standard representative I I 45 50 1 I I 36 52 44 I 1 1 I I I I I I I 1 I I 46 51 53 36 Permutation (c,d) (c,d) (c,d) (c d) I 102 .V 103 '104 .4$ (a,b,c,d) 105 106 (a,c,d,b) 107 (a,c,d) .6, (a,c,d) 109 110 10 56 e (d,c) (a,c) '1112 6113 S 114 61 6115 59 '116 38 43 40 38 43 I 1 I 1 1 I (a,b,c,) 117 (a,b) (b,c) 118 .6, 119 120 (a,b) (a,b,c) 121 .6(122 Permutation (ab) 55 35 49 36 48 47 60 (b,c) (a,c) (a,d,c,b) 57 139 I 11 11 1 I (b,c,d) 140 I Standard S-10 represenFamilies tative (a,c) 37 142 1 I 1 1 1 1 1 I 41 35 55 58 58 58 (a,c) (a,b,c,d) (a,b,d) (a,b,d,c) 58 58 158 I (a,b,c) 55 (c,d) (b,d,c) 36 Table IV S-10 Families of Given S-10 Systems Standard Representative S-10 families I I 1 1 Standard Representative 20 S13, 71 S 25, 26 2 I S 3 S 5, S S I4 221 19 I S 23 224 I6 S I S2 17 18 1 9 I I 1 1 1 S 4, 11 S46,S79 S 90, 91 S 12 S 11, S 66 14 33 15 'Y39,*Y77 16 S 45, 217 18 19 S 1 I I 1 36 I 27 28 S 12, S 6 s 38 S3 I I I 1 S 44, 572 S S 29, 35 S 39 65 9, S 10, 31 S 7, S S 34 35 S 64 32 32 6, 30, 569 S S 68 37 103, 114 S17, S51, 36 S89,105 37 459,4111 S96, S100 7 31 4 29 s 40,80 S 43, 78 25 133 76 S S 47, 73 226 I 592 S I 20 S 2, S 22 S 42, S 75 10 113 1 24, 27, 28 70 22 SSS 3, S 'p8, S41,S74 21 25 I S-10 families 38 S 83, 37 Table IV (continued) Standard Representative I 1 I 1 39 S-10 Families S 61 , 110 40 S98 S99 41 S60 1113 112 42 62 143 3 97 I44 49 85 145 48 S 81 I 1 1 1 I 1 1 I I I 47 86 ,115 107 48 :4,16 $106 49 -114 "v104 50 4'50,''82 51 5 4 S87 52 '°53,-184 53 ,h,88 54 4v56 55 I56 1 Sl01 46 57 X63 63 Standard Representative 102,S115, i/ 122 93 109 S-10 Families '*1 1 58 '1116 ,S117 , S118,S120,121 159 I 1 60 61 95 S S 58, 108 wh( 94 38 Note that the representative of the equivalence class of systems corresponding to S5 S-10 which is used in the partial proof of the Fundamental Theorem is the standard representative 13. Note also that equivalent equivalent S-10 families have systems while nonequivalent S-10 families may or may not have equivalent S-10 system. S-10 See Table IV. Next we introduce Table V. First, we give several definitions, next we explain how to read Table V, then we give the table, and finally we describe the ordering of the I. systems of Table V that makes it apparent 3 that no two of the systems are equivalent. Definition 9. An incongruence of type sometimes simply called a q > 1, [p,q], ruence whose left side is the sum of whose right side is the sum of for which no element of S q p [p,q], p > 1, is an incongelements of elements of S, S, and appears as a term in both sides. An types S-10 [3,1], system consists of incongruences of [2,2], and [2,1], as may be seen in Table V. Definition 10. from an S-10 same left side. A pair of incongruences of type family is two such in [2,1] with the 39 Definition 11. from an S-10 A single incongruence of type [2,1] family is an incongruence that does not belong to a pair. Definition 12. The index of an S-10 system is an ordered quadruple whose first, second, third and fourth entries are the number of incongruences of type incongruences of type type [2,1], [3,1], [2,2], pairs of incongruences of and singles of incongruences of type [2,1], respectively. In Table V the heading for each system is the symbol I., 1<j<61, followed by the index. The incong- ruences of the system are grouped into incongruences of the same type, with incongruences of type [3,1] appear- ing first, incongruences of type [2,2] and incongruences of type appearing at the end. In turn [2,1] [2,1] appearing second, incongruences which form a pair are grouped together. 40 Table V Incongruences of Standard Representatives I 1 (4,0,2,0) 12 (3,1,2,2) a+b+cEd a+b+dEc a+c+dEb b+c+dEa a+btc a+b d c+dta c+d b 1 3 (3,1,2,0) a+b+cEd a+b+dEc a+c+dEb a+b+cEd a+b+dEc a+c+dEb a+btc+d a+btc+d a+btc a+b c a+bEc a+bEd a+dtb a+d c c+dta c+d b b+ctd c +db 1 4 (3,0,4,0) 1 5 (3,0,3,3) 16 (3,0,3,1) a+b+cEd a+b+dEc a+c+dEb a+b+cEd a+b+dEc a+c+dEb a+b+cEd a+b+dEc a+c+dEb a+btc a+b d a+btc a+b d a+btc a+b d a+ctb a+c d a+4b a+cd a+dtb b+dta b+d c a+dtb a+d c c+dta c+d b b+ctd b+ctd c+dta c+d b b+dtc c+dtb a+4c 41 Table V (continued) 1 (3,0,2,2) 7 a+b+cEd a+b+dEc a+c+dEb a+btc a+b d a+cEb a+cEd b+dtc c+dtb 10 (2,2,1,4) (2,2,2,2) 1 8 1 9 (2,2,2,2) a+b+cEd a+b+dEc a+b+ctd a+b+d c a+bEc+d a+cEb+d a+c b+d a+d b+c a+b c a+bEd a+c b a+c d a +cd a+d b a+d c b+d ta b+d c c+dta 11 (2,2,1,4) b+c*d b +dc 1 12 (2,1,4,0) a+b+ctd a+b+dtc a+b+cEd a+b+dEc a+b+cEd a+b+dEc a+btc+d a+c b+d a+c b+d a+d b+c a +bc +d a+bEc a+bEd a+b c a+b c a +cd a+ctd a+dtc a+dtc b+ctd b +dc b+ctd b+dtc a+btc a+b d a+dtb a+d c b+c a b+c d c+d a c+d b 42 Table V (continued) 1 13 (2,1,4,0) 1 14 (2,1,4,0) 1 15 (2,1,3,3) a+b+cfd a +b +cd a+b+4c a+b+dEc a+b+ctd a+b+dtc a+ctb+d a+ctb+d a+btc+d a+btc a+b d a+ctio a+ctca a+b*c a+ctb a+c d a+dtb a+4c a+ctb a+cd. b+d b+d c+d c+d b+cta b+ctd a+dtb a+dtc b+dta b+dte b+ctd a c a b a+W b+dtc c+dtb 1 16 1 (2 ' 3) 3 ' ' 1 17 (2,1,3,2) 1 18 (2,1,3,1) a+b+ctd a+b+d c a+b+ctd a+b+dtc a+b+cr a+ctb+d a+ctb+d a+btc+d a+bte a+1 4d a+btc a+bfd a+btc a+b d a+ctb a+c d. a+ctb a+ctd a+ctb a+c d a+dtb a+dtc a+dr-b b+dtc b+ctd b+dtc b+ctd c+dtb a+d=c b+dtc a+b+d c c+dta c+d b 43 Table V (continued) 1 19 (2,1,3,1) 1 a +b +cd 1 22 20 1 3 (2 ' ' 1) 1 ' 21 (2,1,3,0) a+b+dtc a+b+c#d a+b+dtc a+b+c=d a+b+d=c a+ctb+d a+ctb+d a+ctb+d a+btc a+b*d a+c#b a+ctd a+1:4c a+c=b a+c=d a+d=b a+d=c a+ctb a+ctd b+dta b+idta b+ctcl b+dtc b+4a c+dta b+dtc (2,1,2,4) 1 23 (2,1,2,4) a+btd b+4c 1 24 (2,1,2,3) a+b+cid a+b+d c a+b+ctd a+b+d c a+b+ctd a+b+d c a+btc+d a +cb +d a+ctb+d a+btc a+b d a+b c a+b d a+btc a+b d a+ctio a+d 4 a+c b a+c d a+ctb a+c d a+dtc a+dtc a+dtc b+ctsd b+ctd b+dtc c+dtb b+ctd b +dc c+d*b b+dtc 44 Table V (continued) I 25 (2,1,2,2) I (2,1,2,2) I 27 " (2 1 1 5) a+b+ctd a+b+d c a+b+ctd a+b+d c a+b+ctd a+b+d c a+btc+d a +cb +d a+btc+d a+ctb a+c d a+btc a+b d a+dtc a+ctsd b+ctd a+dtc b+dta b+d c b+cd b+dc c+db a+bt c a+bfc a +cd b +dc c+dta c+d b I 26 28 (2 '0 5" 1) I 29 (2 " 4 2) ' I 30 (2,0,4,2) a+b+ctd a+b+d c a+b+c d a+b+d c a+b+ctd a+b+d c a+btc a+b d a+btc a+bfd a+btc a+b d a+c b a+c d a+ctb a+c d a+clb a+cEd a+d-b a+d c a+d.tb a+dtc b+cla b+c d b+d a b+d c b+ctd b+dtc c+dta c+d b c+d4 a+dfc b+cta b+cfd b +dc c+dta c+d b 45 Table V (continued 1 31 (2,0,3,3) 32 (2,0,3,2) 1 33 (2,0,3,2) a+b+ctd a+b+d c a+b+ctd a+b+d c a+b+cEd a+b+dEc a+btc a+b d a+btc a+b d a+lotc a+ctb a+ctb a+c d a+ctb a+c d a+d tb a+d c a+dtc a+d tb a+d c b+cta b+c d b+dtc c+dtb 1 1 34 (2,0,1,5) a+b d b+ctd. b+cta b+c d b +dc b+dtc I 35 (1I 3 1 14) I 36 " (1 2 4 0) a+b+ctd a+b+d c a+b+ctd a+b+ctd a+btc a+bfd a+b-c+d a+cEb+d a+dEb+c alc+d a+ctd a+c b+d a+btc a+b d a+dtc a+bEc a+bEd b+ctd a +cd b+dtc a+dtc c+dta b+ctd b+dta b+d c b +dc c+dta c+d b a+ctb a+cfd 46 Table V (continued) 1 37 (1,2,3,3) 1 (1,2,3,3) 1 39 (1,2,3,2) a +b +cd a+b+ctd a+b+ctd a+btc+d a+c b+d a+btc+d a+ctb+d a+btc+d a+ctb+d a+btc a+b d a+btc a+b d a+btd a+ct b a+c d a+ctd a+ctb a+c d b+c d b+cta b+c d b +da b +dEc b+dta b+d c c+dta c+d b c+dtb c+dta a+d*c a+sdtb b+c ta. a+d c b +cd 1 38 40 (1,2,2,4) 1 41 (1,2,2,4) 1 42 (1,2,2,3) a+b+ctd a+b+ctd a+b+ctd a+btc+d a +cb +d a+blc+d a+c b+d a +bc a+b:c a+b d a+btc a+b d a+ctb a+c d a+ctd +d a+c b+d a +b c a+btd a+dtc a+ctb a+c d b+ctd b+ctd c+dta b+dtc b+dtc b+la c+dtb c+dtb b+d c a+dtb b+ctd 47 Table V (continued) 1 43 (1,2,2,3) 1 44 (1,1,5,1) I 45 " (1 1 4 2) a+b+ctd a+b+ctd a+b+ctd a+4c+d a+4b+d a+btc+d a+btc+d a+btc a+b c a+bEc a+bEc a+c:b a+c d a+cEb a+cEd a+dtb a+d c a+dtc a+btc a+b d a+ctd b+ctd b+dta b+d c c+dta b+cta b+c d b+dta c+dt a c+d b 146 (1,1,4,2) 1 47 ,,, (1,1,4,2) b+cEa b+cEd b+dtc c+dta c+d b 148 (1,1,4,1) a +b +cd alb+ctd a+b+ctd a+btc+d a+btc+d a+btc+d a+btc a+bfd a+btc a+b c a+btc a+ctb a+c d a+ctd a+ctd a+dtc a+dtb a+d c b+ctcd b+ctd b+d a b+d c b+d a b+d c b+cta b+c d b+dta b+d c c+d a c+d b c+d a c+d b a+1:4d c+dEa c+dEb 48 Table V (continued) I 49 " (1 1 4 0) 150 (1,1,3,3) a+b+ctd a+b+ctd a+b+ctd a+btc+d a+btc+d a+btc+d a+b c a+b d a+btc a+b d a+btc a+b d a+c b a+c d a+ctd a+ctd a+dtc a+dtb b+dta b+cta b +c d b+c a b+c d b+c a b+c=d c+dEa c+d-b c+d a c+d b 1 151 (1,1,3,2) 52 (1,1,2,4) 1 53 (1,1,2,3) c+dta c +d b 1 54 (1,1,2,2) a+b+ctd a+b+ctd a+b+ctd a+btc+d a+btc+d a+btc+d a+btc a+b d a+iptc a+1 *1 a +cd a+ctd a+btc a+b d a +cd a+catb b+ctd a +dc b+ctd b+dtc c+dta b+dtsa c+dta c+4b c+d t a c+d b c +d b 49 Table V (continued) I 55 (0,3,3,3) a+b c+d a+c=b+d a+dEb+c a+btc a+b d a+ctb a+c d a+lb a+d c b+ctid b+dtc c+dtio 258 (0 2 5 0) ' " I 56 (0,2,6,0) 1 a+bEc+d 57 (0,2,5,1) a +c ±b +d a+btc+d a+c b+d a+btc a+b d a+btc a+b d a+cEb a+cEd a+ctb a+c d a+dtb a+d c a+dtb a+d c b+cta b+c d b+dt a b+d c b+ctd b+dta b+d c c+dta c+d b c+dt a c+d b I 59 (0,2,4,.2) I 60 (0,2,4,1) a+btc+d a+ctb+d a+btc+d a+d b+c a+btc+d a+ctb+d a+btc a+b d a+btc a+b d a+btc a+b d a+ctb a+c d a+ctb a+dEb a+dEc b+dta b+d c c+dta c+d b a+dtb a+d c b+cta b+c d b+dtc c+dta c+d b a+ctb a+c d a+dtb b+dta b+d c c+dta c+d b 50 Table V (continued) 1 61 (0,2,4,0) a+ctb+d a+d b+c a+ctb a+c d a+dtb a+catc b+cta b +c d b+dta b +d c 51 The way we obtain and order the given in Table V is use the S-10 systems S-10 systems of the families order the equivalence classes of 1<i<122, I. S-10 systems to which they belong, discard duplicates, and then identify a certain representative from each of the remaining equivalence classes which we have called the standard representative I.3 . First, we partition the original 122 S-10 systems by index and call the parts obtained parts of rank one. We order the parts of rank one in a lexicographically decreasing manner on the index. The systems from S-10 two different parts of rank one are not equivalent to each In case a part of rank one consists of only one other. S-10 systems this S-10 standard representative system is taken to be its I.3 . Next, we partition the parts of rank one with more than one S-10 system according to the structure of the system of incongruences of types [3,1] and parts obtained are called parts of rank two. rank one with more than one S-10 with only one incongruence of type is performed on formed into S [2,2]. The If a part of system has a system [3,1], a permutation so that this incongruence is trans- a+b+ctd. If there are two [3,1]'s, a 52 permutation is performed on a+b+ctd formed into and so that they are trans- S If there are three a+b-i-dtc. [3,1] 's, a permutation is performed on are transformed into In case there are no a+b+0c, a+b+ctd, or four [3,1] 's S not perform any permutation on so that they a+c+Ob. and [3,1] 's, we do S. Once the above procedure is completed on each of the parts of rank one that have more than one 5 -10 system, each of these parts consists of systems with identical [3,1] 's. Now, we consider the analysis a permutation system of S-10 [3,1] 's P from an In the following [2,2] 's. on is allowed only if the S S-10 part of rank one is invariant under system belonging to a P. If a part of rank one with more than one S-10 system has a system with only one incongruence of type this incongruence is transformed, if possible, [2,2], into a+btc+d by a permutation on transformed, if possible, into on S. Otherwise, it is a+ctb+d by a permutation If this also is not possible the incongruence is S. a+dtb+c. If a part of the above kind has an where there are two incongruences of type S-10 [2,2], incongruences are transformed, if possible into system these a+btc+d 53 and a+cOp+d by a permutation on S. are transformed, if possible, into by a permutation on are no and or three [2,2]'s permutation on a+btc+d and a +d4b +c If this also is not possible the S. a+ctb+d incongruences are Otherwise, they a+dtb+c. [2,2]'s In case there we do not perform any S. We have completed the second partitioning. A part of rank two consists of systems from a part of rank S-10 one which have identical subsystems of [3,1] incongruences after the permutations on and [2,2] mentioned in S the preceeding paragraph have been performed. Next, we order the parts of rank two. The parts of rank two, that contain one subsystem of incongruences of type [2,2] are ordered in such a way that a part that contains systems with incongruence a+btc+d ruence preceds a part that contains systems with incong- a+cb+d, which in turn preceds a part that con- tains systems with incongruence a+dtb+c. Similarly, the parts of rank two that contain two subsystems of incongruences of type [2,2] are ordered in such a way that a part that contains systems with incongruences and a+ctb+d incongruences a+btc+d precedes a part that contains systems with a+btc+d and a +db +c, which in turn pre- cedes a part that contains systems with incongruences a+ctb+d and a+dtb+c. 54 In case a part of rank two consists of only one S-10 system, this S-10 system is taken to be its standard representative. We now complete the process of ordering and identifying the systems of each part of rank two, with S-10 more than one system; these systems that have the same index, the same [3,11's and the same this purpose we label the 12 possible [2,2]'s. For [2,1]'s of an S-10 system of a part of rank two by increasing digits base 13 as follows: Label Incongruence 1 a+lotc 2 a+14d 3 a+ctho 4 a+ctid 5 a+dtlo 6 a +dEc 7 b+cta 8 b+ctcl 9 b+dta a b+dtc c+dta y c+idta 55 Corresponding to each subsystem of incongruences of type there is a number that will be called a [2,1] This tag number is formed by increasing tag number. digits, where the digits are the labels of the congruences. system a+btd, c+dtb; Next, we perform a permutation on the S-10 [3,1]'s is S 1278. that trans- system of each part of rank two, leaving and the number is minimized. S-10 in- For instance, the tag number of the sub- a+btb+c, forms the [2,1] invariant so that the tag [2,2]'s Once this is done, we order the systems in each part of rank two in a lexicographi- cally increasing manner on the tag numbers. shows that no two of these to each other. S-10 Hence, these This ordering systems are equivalent S-10 systems with smallest tag number are the standard representatives, of Table V. In Table VI that follows we list the I. S-10 systems in each of the parts of rank two with more than one 3 S-10 system. Included in the table are their indexes, their incongruences of type missible permutations on and 5, [2,2], and the so called per- that leave the [3,1]'s, [2,2]'s invariant, used to get the smallest tag numbers. 56 Table VI S-10 Systems in Each Part of Rank Two With More Than One 5 -10 System . Incongruences Permissible Permutations (2,1,4,0) a+c t b+d (a,b)(c,d),e (2,1,3,1) a+c t b+d (a,b)(c,d),e Index I. .1 I 13? 119' I 29' I I I 14 20 30 (2,0,4,2) [2,2] None (a,b)(c,d), (a,b) (c,d) ,e 1 321 1 33 (2,0,3,2) None (a,b),(c,d), (a,b) (c,d) ,e 1 371 1401 1 I 45 42' ,I 1 I 1 38 41 43 1 46' 47 (1,2,3,3) a+b*c+d,a+cb+d (b,c), e (1,2,2,4) a+btc+d,a+ctb+d (b,c), e (1,2,2,3) a+btc+d,a+ctb+d (b,c) , (1,1,4,2) a+b t c+d (a,b), e e 57 An alternating ordering of all the equivalence classes of of the standard representatives Table V 3 which makes clear that they are pairwise not equivalent could have been obtained by a single lexicographical ordering similar to the one used to order the standard representatives I.3 of Table VI. However, the ordering that we have chosen gives more insight into the structure ofthesystemsI.,and it is obtained more easily. 58 Epilogue We give several problems to which one is lead by this thesis. There are 61 entries in Table III, exactly half the number of entries in Table II. An interesting prob- lem is to determine if this is a special case of a more general theorem for families of subsets and the corresponding system of incongruences. A further problem is to obtain the relationship between the total number of families and the total number of corresponding systems. This latter problem has not even been solved for families and S-10 S-10 systems. A different problem is to determine if any of the 61 systems of Table III lead to a variation in the proof of the Fundamental Theorem, and if they do, if the proofs are simpler. Also, a problem is to find a new proof of the Fundamental Theorem that will provide a method of evaluating the function arbitrary k > 5. 14(k,m) for k=5, or perhaps even for 59 Bibliography (1) Not yet published proof of the Fundamental Theorem, by Robert D. Stalley, Oregon State University. (2) Unpublished notes by Robert D. Stalley.