=Paper= {{Paper |id=Vol-3754/paper06 |storemode=property |title=Algebraic (non) relations among polyzetas |pdfUrl=https://ceur-ws.org/Vol-3754/paper06.pdf |volume=Vol-3754 |authors=Vincel Hoang Ngoc Minh |dblpUrl=https://dblp.org/rec/conf/sycss/Minh24 }} ==Algebraic (non) relations among polyzetas== https://ceur-ws.org/Vol-3754/paper06.pdf
                         Algebraic (non) Relations Among Polyzetas
                         V. Hoang Ngoc Minh1
                         1
                             University of Lille, 1 Place DΓ©liot, Lille, 59024, France


                                         Abstract
                                         Two confluent rewriting systems in noncommutatives polynomials are constructed using the equations allowing
                                         the identification of the local coordinates (of second kind) of the graphs of the 𝜁 polymorphism as being (shuffle
                                         or quasi-shuffle) characters and bridging two algebraic structures of polyzetas.
                                             In each system, the left side of each rewriting rule corresponds to the leading monomial of the associated
                                         homogeneous in weight polynomial while the right side is canonically represented on the algebra generated by
                                         irreducible terms which encode an algebraic basis of the algebra of polyzetas.
                                             These polynomials are totally lexicographically ordered and generate the kernels of the 𝜁 polymorphism
                                         meaning that the free algebra of polyzetas is graded and the irreducible polyzetas are transcendent numbers,
                                         algebraically independent.

                                         Keywords
                                         Polylogarithms, Hamonic Sums, Polyzetas, Rewritting Systems




                         1. Introduction
                         For any π‘Ÿ β‰₯ 1 and (𝑠1 , . . . , π‘ π‘Ÿ ) ∈ Nβ‰₯1 , for any 𝑧 ∈ C ΛœοΈ‚
                                                                                    βˆ– {0, 1} and 𝑛 β‰₯ 1, let
                                                                                                                                                            𝑛
                                                                         βˆ‘οΈ                 𝑧 𝑛1                                                           βˆ‘οΈ                      1
                                       Li𝑠1 ,...,π‘ π‘Ÿ (𝑧) :=                                                    and H𝑠1 ,...,π‘ π‘Ÿ (𝑛) :=                                               .   (1)
                                                                                       𝑛𝑠11 . . . π‘›π‘ π‘Ÿπ‘Ÿ                                                             𝑛𝑠11 . . . π‘›π‘ π‘Ÿπ‘Ÿ
                                                                  𝑛1 >...>π‘›π‘Ÿ >0                                                                      𝑛1 >...>π‘›π‘Ÿ >0

                         which are respectively called polylogarithm and harmonic sum.
                           Let β„‹π‘Ÿ be {(𝑠1 , . . . , π‘ π‘Ÿ ) ∈ Nπ‘Ÿβ‰₯1 , 𝑠1 > 1}. Then, for any (𝑠1 , . . . , π‘ π‘Ÿ ) belonging to β„‹π‘Ÿ , by a Abel’s
                         theorem, the following limits exist and are called polyzetas1 [9, 10]

                                                                                                                π‘›βˆ’π‘ 
                                                                                                       βˆ‘οΈ
                               𝜁(𝑠1 , . . . , π‘ π‘Ÿ ) := lim Li𝑠1 ,...,π‘ π‘Ÿ (𝑧) = lim H𝑠1 ,...,π‘ π‘Ÿ (𝑛) =               1
                                                                                                                    1
                                                                                                                      . . . π‘›βˆ’π‘ 
                                                                                                                             π‘Ÿ .
                                                                                                                                π‘Ÿ
                                                                                                                                      (2)
                                                                  𝑧→1                               𝑛→+∞
                                                                                                                                           𝑛1 >...>π‘›π‘Ÿ >0


                           Euler earlier studied polyzetas, in particular {𝜁(𝑠1 , 𝑠2 )}π‘Ÿβ‰₯1
                                                                                       𝑠1 >1,𝑠2 β‰₯1 in classic analysis. He stated that
                         𝜁(6, 2) can not be expressed on 𝜁(2), ..., 𝜁(8) and proved [6]
                                                                                          π‘ βˆ’2
                                                                         1 (︁             βˆ‘οΈ                  )︁
                                            𝜁(2, 1) = 𝜁(3) and 𝜁(𝑠, 1) =      π‘ πœ(𝑠 + 1) βˆ’     𝜁(𝑗 + 1)𝜁(𝑠 βˆ’ 𝑗) , 𝑠 > 1.                                                                (3)
                                                                         2
                                                                                                                                   𝑗=1


                            The {𝜁(𝑠1 , . . . , π‘ π‘Ÿ )}π‘Ÿβ‰₯1
                                                     𝑠1 >1,𝑠2 ,...,π‘ π‘Ÿ β‰₯1 are also called multi zeta values (MZV for short) [13] or Euler-
                         Zagier sums [2] and the numbers π‘Ÿ and 𝑠1 + . . . + π‘ π‘Ÿ are, respectively, depth and weight of 𝜁(𝑠1 , . . . , π‘ π‘Ÿ ).
                         One can also found in their biographies some recent applications of these special values in algebraic
                         geometry, Diophantine equations, knots invariants of Vassiliev-Kontsevich, modular forms, quantum
                         electrodynamic, . . . .
                            Many new linear relations for polyzetas are detected using LLL type algorithms in high performance
                         computing and the truncations of {𝜁(𝑠1 , . . . , π‘ π‘Ÿ )}π‘Ÿβ‰₯1                                                  π‘Ÿβ‰₯1
                                                                                        𝑠1 >1,𝑠2 ,...,π‘ π‘Ÿ β‰₯1 , i.e. {H𝑠1 ,...,π‘ π‘Ÿ (𝑛)}𝑠1 >1,𝑠2 ,...,π‘ π‘Ÿ β‰₯1 [1,
                         2]. In this approach, the main problem is to detect with near certainty which polyzetas can not be

                          SCSS 2024: 10th International Symposium on Symbolic Computation in Software Science, August 28–30, 2024, Tokyo, Japan
                          $ vincel.hoang-ngoc-minh@univ-lille.fr (V. Hoang Ngoc Minh)
                           0000-0002-3510-7639 (V. Hoang Ngoc Minh)
                                         Β© 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
                         1
                             Polyzeta is the contraction of polymorphism and of zeta (see (5)–(6) below).

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                                                                                                                28
expressed on {𝜁(2), . . . , 𝜁(𝑠 + π‘˜)} and are qualified as new constants (as for Euler’s 𝜁(6, 2)) [2]. Such
polyzetas could be Q-algebraically independent on these zeta values (see Example 1 below) and the
polyzetas could be transcendent numbers (see [9, 10] for proof). Checking linear relations among
{𝜁(𝑠1 , . . . , π‘ π‘Ÿ )}π‘Ÿβ‰₯1
                     𝑠1 >1,𝑠2 ,...,π‘ π‘Ÿ β‰₯1 , Zagier stated that the Q-module generated by MZV is graded (see [9, 10]
                      2≀𝑠1 +...+π‘ π‘Ÿ ≀12
for proof) and guessed (see [7, 8, 12] for other algebraic checks)
Conjecture 1 ([13]). Let π‘‘π‘˜ := dim π’΅π‘˜ and π’΅π‘˜ := spanQ {𝜁(𝑀)}π‘Ÿβ‰₯1
                                                            𝑠1 >1,𝑠2 ,...,π‘ π‘Ÿ β‰₯1 , for π‘˜ β‰₯ 1. Then
                                                                                                  𝑠1 +...+π‘ π‘Ÿ =π‘˜
𝑑1 = 0, 𝑑2 = 𝑑3 = 1 and π‘‘π‘˜ = π‘‘π‘˜βˆ’3 + π‘‘π‘˜βˆ’2 , for π‘˜ β‰₯ 4.
  Studying Conjecture 1, in continuation with [3, 5] by a symbolic approach, this work provides more
explanations and consequences regarding the algorithm LocalCoordinateIdentification, partially
implemented in [3] and briefly described in [4].
  It applies an Abel like theorem concerning the generating series of {H𝑠1 ,...,π‘ π‘Ÿ }π‘ π‘Ÿβ‰₯1       1 ,...,π‘ π‘Ÿ β‰₯1
                                                                                                            (resp.
               π‘Ÿβ‰₯1
{Li𝑠1 ,...,π‘ π‘Ÿ }𝑠1 ,...,π‘ π‘Ÿ β‰₯1 ) [5], over the alphabet π‘Œ = {π‘¦π‘˜ }π‘˜β‰₯1 (resp. 𝑋 = {π‘₯0 , π‘₯1 }) generating the free
monoid (π‘Œ * , 1π‘Œ * ) (resp. (𝑋 * , 1𝑋 * )) with respect to the concatenation (denoted by conc and omitted
when there is no ambiguity), the set of Lyndon words β„’π‘¦π‘›π‘Œ (resp. ℒ𝑦𝑛𝑋) and the set of polynomials,
QβŸ¨π‘Œ ⟩ (resp. QβŸ¨π‘‹βŸ©). This theorem exploits the indexations of polylogarithms and harmonic sums in (1)
by words, i.e. [9, 10]
                 Liπ‘₯π‘Ÿ0 (𝑧) = logπ‘Ÿ (𝑧)/π‘Ÿ!, Liπ‘₯𝑠1 βˆ’1 π‘₯ ...π‘₯π‘ π‘Ÿ βˆ’1 π‘₯ = Li𝑠1 ,...,π‘ π‘Ÿ , H𝑦𝑠1 ...π‘¦π‘ π‘Ÿ = H𝑠1 ,...,π‘ π‘Ÿ .                         (4)
                                                       0        1    0         1

It follows that the isomorphism of algebras Hβˆ™ : (QβŸ¨π‘Œ ⟩,   ) βˆ’β†’ (Q{H𝑀 }π‘€βˆˆπ‘Œ * , Γ—) (resp. Liβˆ™ :
(QβŸ¨π‘‹βŸ©, βŠ”βŠ” ) βˆ’β†’ (Q{Li𝑀 }π‘€βˆˆπ‘‹ * , Γ—)), mapping 𝑒 (resp. 𝑣) to H𝑒 (resp. Li𝑣 ), induce the following
surjective polymorphism [9, 10]
                                 (Q1𝑋 * βŠ• π‘₯0 QβŸ¨π‘‹βŸ©π‘₯1 , βŠ”βŠ” , 1𝑋 * )
                          𝜁:                                       βˆ’β†  (𝒡, Γ—, 1),                                                      (5)
                               (Q1π‘Œ * βŠ• (π‘Œ βˆ– {𝑦1 })QβŸ¨π‘Œ ⟩, , 1π‘Œ * )
                                                       π‘₯0 π‘₯𝑠11 βˆ’1 . . . π‘₯0 π‘₯1π‘ π‘˜ βˆ’1
                                                                                      β†¦βˆ’β†’ 𝜁(𝑠1 , . . . , π‘ π‘Ÿ ),                        (6)
                                                             𝑦𝑠1 . . . π‘¦π‘ π‘˜
where 𝒡 is the Q-algebra generated by polyzetas (not linearly free [13]) and the product                                       (resp. βŠ”βŠ” )
is defined, for any 𝑒, 𝑣, 𝑀 ∈ π‘Œ * (resp. 𝑋 * ) and 𝑦𝑖 , 𝑦𝑗 ∈ π‘Œ (resp. π‘₯, 𝑦 ∈ 𝑋), by
            𝑀     1π‘Œ * = 1π‘Œ *      𝑀 = 𝑀 and 𝑦𝑖 𝑒                𝑦𝑗 𝑣 = 𝑦𝑖 (𝑒      𝑦𝑗 𝑣) + 𝑦𝑗 (𝑦𝑖 𝑒     𝑣) + 𝑦𝑖+𝑗 (𝑒      𝑣),         (7)
                   (resp. 𝑀 βŠ”βŠ” 1𝑋 * = 1𝑋 * βŠ”βŠ” 𝑀 = 𝑀 and π‘₯𝑒 βŠ”βŠ” 𝑦𝑣 = π‘₯(𝑒 βŠ”βŠ” 𝑦𝑣) + 𝑦(π‘₯𝑒 βŠ”βŠ” 𝑣)).                                          (8)
   The graphs of the 𝜁 polymorphism in (5)–(6) are expressed as                                   (resp. βŠ”βŠ” )-group like series as
follows [9, 10]
                                             β†˜
                                             ∏︁                                              β†˜
                                                                                             ∏︁
                                   𝛾𝑦1                         𝜁(Σ𝑙 )Π𝑙
                         𝑍𝛾 = 𝑒                            𝑒               and π‘βŠ”βŠ” =                   π‘’πœ(𝑆𝑙 )𝑃𝑙 ,                    (9)
                                         π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 }                                   π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹

where {Π𝑀 }π‘€βˆˆπ‘Œ * (resp. {𝑃𝑀 }π‘€βˆˆπ‘‹ * ) is the PBW-Lyndon basis (of the Lie polynomilas {Π𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ (resp.
{𝑃𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹ ) basis) in duality with {Σ𝑀 }π‘€βˆˆπ‘‹ * (resp. {𝑆𝑀 }π‘€βˆˆπ‘‹ * ) (containing the basis {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ (resp.
{𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ )), on the     (resp. βŠ”βŠ” )-bialgebra [9, 10]. Finally, the identification of their local coordinates
(of second kind in the group of group like series) in the equations bridging the lagebraic structures of
polyzetas, i.e. [5]
                                                π‘˜ /π‘˜                                                         π‘˜
                             βˆ‘οΈ€                                                              βˆ‘οΈ€
              𝑍𝛾 = 𝑒𝛾𝑦1 βˆ’      π‘˜β‰₯2 𝜁(π‘˜)(βˆ’π‘¦1 )          πœ‹π‘Œ π‘βŠ”βŠ”        and π‘βŠ”βŠ” = π‘’βˆ’π›Ύπ‘₯1 +         π‘˜β‰₯2 𝜁(π‘˜)(βˆ’π‘₯1 ) /π‘˜     πœ‹π‘‹ 𝑍𝛾 ,         (10)
provides the algebraic relations among {𝜁(Σ𝑙 )}π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } (resp. {𝜁(𝑆𝑙 )}π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ ), independent on
𝛾, leading to the algebraic bases for Im 𝜁 and the homogenous polynomials generating ker 𝜁 [9, 10] (see
[3] for examples), with2 the morphism of monoids πœ‹π‘Œ : 𝑋 * π‘₯1 βˆ’β†’ π‘Œ * (resp. πœ‹π‘‹ : π‘Œ * βˆ’β†’ 𝑋 * π‘₯1 ) maps
π‘¦π‘˜ to π‘₯π‘˜βˆ’1             π‘˜βˆ’1
        0 π‘₯1 (resp. π‘₯0 π‘₯1 to π‘¦π‘˜ ).
2
    There are one-to-one correspondences over the above monoids and that generated by Nβ‰₯1 , i.e π‘₯𝑠01 βˆ’1 π‘₯1 . . . π‘₯𝑠0π‘Ÿ βˆ’1 π‘₯1 ∈
    𝑋 * π‘₯1 β‡Œπœ‹πœ‹π‘Œπ‘‹ 𝑦𝑠1 . . . π‘¦π‘ π‘Ÿ ∈ π‘Œ * ↔ (𝑠1 , . . . , π‘ π‘Ÿ ) ∈ N*β‰₯1




                                                                          29
2. Rewriting among {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } and among {𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹
For convenience, 𝒳 denotes 𝑋 or π‘Œ and if 𝒳 = 𝑋 then gDIV = 𝑋 and CONV = π‘₯0 𝑋 * π‘₯1 else
gDIV = {𝑦1 } and CONV = (π‘Œ βˆ– {𝑦1 })π‘Œ * . It follows that ℒ𝑦𝑛𝒳 βˆ– gDIV βŠ‚ CONV.
  Expressing, i.e replacing β€œ=” by β€œβ†’β€, the relations among polyzetas in [3] become the rewriting rules
among polyzetas and yield the following increasing sets of irreducible polyzetas (see Example 1 below)
                               𝒳 ,≀2            𝒳 ,≀𝑝            𝒳 ,∞
                              π’΅π‘–π‘Ÿπ‘Ÿ   βŠ‚ Β· Β· Β· βŠ‚ π’΅π‘–π‘Ÿπ‘Ÿ   βŠ‚ Β· Β· Β· βŠ‚ π’΅π‘–π‘Ÿπ‘Ÿ                                  (11)

and their images by a section of 𝜁 (see Example 2 below)

                              ℒ𝒳 ,≀2
                               π‘–π‘Ÿπ‘Ÿ   βŠ‚ Β· Β· Β· βŠ‚ ℒ𝒳 ,≀𝑝
                                                π‘–π‘Ÿπ‘Ÿ   βŠ‚ Β· Β· Β· βŠ‚ ℒ𝒳 ,∞
                                                                 π‘–π‘Ÿπ‘Ÿ ,                                (12)

such that the following restriction is an isomorphism of algebras [9, 10]
                                                      𝒳 ,∞
                               𝜁 : Q[β„’βˆž
                                      π‘–π‘Ÿπ‘Ÿ (𝒳 )] βˆ’β†’ Q[π’΅π‘–π‘Ÿπ‘Ÿ ] = 𝒡.                                      (13)

Note that one also has

                           ℒ𝒳 ,∞
                                           ℒ𝒳 ,≀𝑝      𝒳 ,∞
                                                                        ℒ𝒳 ,≀𝑝
                                     ⋃︁                           ⋃︁
                            π‘–π‘Ÿπ‘Ÿ =           π‘–π‘Ÿπ‘Ÿ   and β„’π‘–π‘Ÿπ‘Ÿ  =            π‘–π‘Ÿπ‘Ÿ .                        (14)
                                     𝑝β‰₯2                          𝑝β‰₯2

  Now, let us describe the algorithm LocalCoordinateIdentification below which brings aditional
results to [3]. It provides the rewriting systems (Q1𝑋 * βŠ• π‘₯0 QβŸ¨π‘‹βŸ©π‘₯1 , ℛ𝑋      π‘–π‘Ÿπ‘Ÿ ) and (Q1π‘Œ * βŠ• (π‘Œ βˆ–
{𝑦1 })QβŸ¨π‘Œ ⟩, β„›π‘Œπ‘–π‘Ÿπ‘Ÿ ) which are without critical pairs, noetherian, confluent and precisely contains the
above sets (see (11)–(12)) and, on the other hand, the set of homogenous in weight polynomials, be-
longing to Q[ℒ𝑦𝑛𝒳 βˆ– gDIV], which are image by a section of the surjective 𝜁 polymorphism from
{𝜁(𝑄𝑙 ) = 0}π‘™βˆˆβ„’π‘¦π‘›π’³ βˆ–gDIV . It is denoted by 𝒬𝒳 :

                                     𝒬𝒳 = {𝑄𝑙 }π‘™βˆˆβ„’π‘¦π‘›π’³ βˆ–gDIV                                           (15)

and generates the shuffle or quasi-shuffle ideal ℛ𝒳 inside ker 𝜁 as follows

                                    ℛ𝒳 := spanQ 𝒬𝒳 βŠ† ker 𝜁.                                           (16)

   For any 𝑝 β‰₯ 2 and 𝑙 ∈ ℒ𝑦𝑛𝑝 𝒳 := {𝑙 ∈ ℒ𝑦𝑛𝒳 |(𝑙) = 𝑝}, any nonzero homogenous in weight
polynomial (belonging to 𝒬𝒳 ) 𝑄𝑙 = Σ𝑙 βˆ’ Ξ₯𝑙 (resp. 𝑄𝑙 = 𝑆𝑙 βˆ’ π‘ˆπ‘™ ) is led by Σ𝑙 (resp. 𝑆𝑙 ) being
transcendent over Q[ℒ𝒳   ,≀𝑝
                       π‘–π‘Ÿπ‘Ÿ ] and Ξ₯𝑙 = 𝑄𝑙 βˆ’ Σ𝑙 (resp. π‘ˆπ‘™ = 𝑄𝑙 βˆ’ 𝑆𝑙 ) is canonically represented in
Q[ℒ𝒳  ,≀𝑝
    π‘–π‘Ÿπ‘Ÿ ]. Then let Σ𝑙 β†’ Ξ₯𝑙 and 𝑆𝑙 β†’ π‘ˆπ‘™ be the rewriting rules, respectively, of

                β„›π‘Œπ‘–π‘Ÿπ‘Ÿ := {Σ𝑙 β†’ Ξ₯𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } and ℛ𝑋
                                                      π‘–π‘Ÿπ‘Ÿ := {𝑆𝑙 β†’ π‘ˆπ‘™ }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ .                     (17)

On the other hand, the following assertions are equivalent (see Example 2 below)
   1. 𝑄𝑙 = 0
   2. Σ𝑙 ∈ β„’π‘Œ,≀𝑝               𝑋,≀𝑝
             π‘–π‘Ÿπ‘Ÿ (resp. 𝑆𝑙 ∈ β„’π‘–π‘Ÿπ‘Ÿ ),
   3. Σ𝑙 β†’ Σ𝑙 (resp. 𝑆𝑙 β†’ 𝑆𝑙 ).
                                                                           𝒳 ,∞
  In the other words, the ordering over ℒ𝑦𝑛𝒳 induces the ordering over β„’π‘–π‘Ÿπ‘Ÿ     , ℛ𝒳 , ℛ𝒳
                                                                                        π‘–π‘Ÿπ‘Ÿ and, in the
                                𝑋                                   π‘Œ
systems (Q1𝑋 * βŠ• π‘₯0 QβŸ¨π‘‹βŸ©π‘₯1 , β„›π‘–π‘Ÿπ‘Ÿ ) and (Q1π‘Œ * βŠ• (π‘Œ βˆ– {𝑦1 })QβŸ¨π‘Œ ⟩, β„›π‘–π‘Ÿπ‘Ÿ ),
   1. each irreducible term, in ℒ𝒳 ,∞
                                 π‘–π‘Ÿπ‘Ÿ , is an element of the algebraic basis {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } of (Q1π‘Œ * βŠ•
      (π‘Œ βˆ– {𝑦1 })QβŸ¨π‘Œ ⟩, ) (resp. {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ of (Q1𝑋 * βŠ• π‘₯0 QβŸ¨π‘‹βŸ©π‘₯1 , βŠ”βŠ” )),
                                                                                       𝒳 ,∞
   2. each rewriting rule, in ℛ𝒳
                               π‘–π‘Ÿπ‘Ÿ , admits the left side being transcendent over Q[β„’π‘–π‘Ÿπ‘Ÿ ] and the right
      side being canonically represented in Q[ℒ𝒳     ,∞
                                                   π‘–π‘Ÿπ‘Ÿ ]. The difference of these two sides belongs to the
      ordered ideal ℛ𝒳 of Q[ℒ𝑦𝑛𝒳 βˆ– gDIV].




                                                   30
LocalCoordinateIdentification
 𝒳 ,∞
π’΅π‘–π‘Ÿπ‘Ÿ  := {}; ℒ𝒳 ,∞         𝒳
              π‘–π‘Ÿπ‘Ÿ := {}; β„›π‘–π‘Ÿπ‘Ÿ := {}; 𝒬𝒳 := {};
for 𝑝 ranges in 2, . . . , ∞ do
       for 𝑙 ranges in the totally ordered ℒ𝑦𝑛𝑝 𝒳 do
        identify βŸ¨π‘π›Ύ |Π𝑙 ⟩ in 𝑍𝛾 = 𝐡(𝑦1 )πœ‹π‘Œ π‘βŠ”βŠ” and βŸ¨π‘βŠ”βŠ” |𝑃𝑙 ⟩ in π‘βŠ”βŠ” = 𝐡(π‘₯1 )βˆ’1 πœ‹π‘‹ 𝑍𝛾 ;
        by elimination, obtain equations on {𝜁(Σ𝑙′ )} 𝑙′ βˆˆβ„’π‘¦π‘›π‘ π‘Œ and on {𝜁(𝑆𝑙′ )} 𝑙′ βˆˆβ„’π‘¦π‘›π‘ 𝑋 ;
                                                                                    𝑙′ βͺ―𝑙                           𝑙′ βͺ―𝑙
              express3 the equations led by 𝜁(Σ𝑙 ) and by 𝜁(𝑆𝑙 ) as rewriting rules;
                                          π‘Œ,∞     π‘Œ,∞               π‘Œ,∞     π‘Œ,∞
              if 𝜁(Σ𝑙 ) β†’ 𝜁(Σ𝑙 ) then π’΅π‘–π‘Ÿπ‘Ÿ := π’΅π‘–π‘Ÿπ‘Ÿ βˆͺ {𝜁(Σ𝑙 )} and β„’π‘–π‘Ÿπ‘Ÿ := β„’π‘–π‘Ÿπ‘Ÿ βˆͺ {Σ𝑙 }
               else β„›π‘Œ          π‘Œ
                        π‘–π‘Ÿπ‘Ÿ := β„›π‘–π‘Ÿπ‘Ÿ βˆͺ {Σ𝑙 β†’ Ξ₯𝑙 } and π’¬π‘Œ := π’¬π‘Œ βˆͺ {Σ𝑙 βˆ’ Ξ₯𝑙 };
                                                𝑋,∞         𝑋,∞                             𝑋,∞   𝑋,∞
       if 𝜁(𝑆𝑙 ) β†’ 𝜁(𝑆𝑙 ) then π’΅π‘–π‘Ÿπ‘Ÿ := π’΅π‘–π‘Ÿπ‘Ÿ βˆͺ {𝜁(𝑆𝑙 )} and β„’π‘–π‘Ÿπ‘Ÿ := β„’π‘–π‘Ÿπ‘Ÿ                                 βˆͺ {𝑆𝑙 }
        else ℛ𝑋           𝑋
                 π‘–π‘Ÿπ‘Ÿ := β„›π‘–π‘Ÿπ‘Ÿ βˆͺ {𝑆𝑙 β†’ π‘ˆπ‘™ } and 𝒬𝑋 := 𝒬𝑋 βˆͺ {𝑆𝑙 βˆ’ π‘ˆπ‘™ }
     end_for
end_for

      With the notations introduced in (11)–(17), on also has4
                                                𝒳 ,∞
Proposition 1 ([9, 10]).   1. ℛ𝒳 = ker 𝜁 and Q[π’΅π‘–π‘Ÿπ‘Ÿ  ] = 𝒡 = Im 𝜁.
   2. Q[{𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ ] = ℛ𝑋 βŠ• Q[β„’π‘–π‘Ÿπ‘Ÿ ] and Q[{Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } ] = β„›π‘Œ βŠ• Q[β„’π‘Œ,∞
                                  𝑋,∞
                                                                             π‘–π‘Ÿπ‘Ÿ ].

Proof –
       1. Let 𝑄 ∈ ker 𝜁, βŸ¨π‘„|1𝒳 * ⟩ = 0. Then 𝑄 = 𝑄1 + 𝑄2 (with 𝑄2 ∈ Q[ℒ𝒳        ,∞
                                                                              π‘–π‘Ÿπ‘Ÿ ] and 𝑄1 ∈ ℛ𝒳 ). Hence,
          decomposing in {𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ (resp. {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } ) and reducing by ℛ𝒳   π‘–π‘Ÿπ‘Ÿ , it follows that
          𝑄 ≑ℛ𝒳 𝑄1 ∈ ℛ𝒳 and then the expected result.
                   π‘–π‘Ÿπ‘Ÿ
          Let 𝑀 ∈ CONV. Decomposing in {𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ (resp. {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } ) and reducing by ℛ𝒳        π‘–π‘Ÿπ‘Ÿ ,
                       𝒳 ,∞                                       𝒳 ,∞
          𝑀 ∈ Q[β„’π‘–π‘Ÿπ‘Ÿ ]. Applying (13) and (5)–(6), 𝜁(𝑀) ∈ Q[π’΅π‘–π‘Ÿπ‘Ÿ ] = 𝒡 and 𝒡 = Im 𝜁. Extending by
          linearrity, it follows the expected result.
       2. For any 𝑀 ∈ CONV, decomposing in {𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ (resp. {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } ) and reducing by
                               𝒳 ,∞
          ℛ𝒳 π‘–π‘Ÿπ‘Ÿ , 𝜁(𝑀) ∈ Q[π’΅π‘–π‘Ÿπ‘Ÿ ]. By linearity, if 𝑃 ∈ Q[{𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ ] (resp. Q[{Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } ]) and
                                                𝒳 ,∞
          𝑃 ∈ / ker 𝜁 βŠ‡ ℛ𝒳 then 𝜁(𝑃 ) ∈ Q[π’΅π‘–π‘Ÿπ‘Ÿ       ].
                                                    𝒳 ,∞
          On the other hand, if 𝑄 ∈ ℛ𝒳 ∩ Q[β„’π‘–π‘Ÿπ‘Ÿ ] then, by (16), 𝜁(𝑄) = 0 and then, by (13), 𝑄 = 0
          yielding the expected result.
β–‘
                                                             𝒳 ,∞                                   ⨁︀
Theorem 1 ([9, 10]). The Q-algebra 𝒡 is freely generated by π’΅π‘–π‘Ÿπ‘Ÿ  and 𝒡 = Q1 βŠ•                           π‘˜β‰₯2 π’΅π‘˜ .

                                                               𝒳 ,∞
Proof – By (13) and Proposition 1, 𝒡 is freely generated by π’΅π‘–π‘Ÿπ‘Ÿ    and ker 𝜁, being generated by the
homogenous in weight polynomials {𝑄𝑙 }π‘™βˆˆβ„’π‘¦π‘›π’³ βˆ–gDIV , is graded. With the notations in Conjecture 1,
being isomorphic to Q1π‘Œ * βŠ• (π‘Œ βˆ– {𝑦1 })QβŸ¨π‘Œ ⟩/ ker 𝜁 and to Q1𝑋 * βŠ• π‘₯0 QβŸ¨π‘‹βŸ©π‘₯1 / ker 𝜁, 𝒡 is also graded.
β–‘

Corollary 1 ([9, 10]). Let 𝑃 ∈ ℒ𝒳 ,∞
                                π‘–π‘Ÿπ‘Ÿ . Then 𝜁(𝑃 ) is a transcendent number.

Proof – Let 𝑃 ∈ QβŸ¨π’³ ⟩ and 𝑃 ∈        / ker 𝜁, being homogenous in weight, or 𝑃 ∈ CONV. Since
π’΅π‘˜ π’΅π‘˜β€² βŠ‚ π’΅π‘˜+π‘˜β€² (π‘˜, π‘˜ β€² β‰₯ 1) then each monomial (𝜁(𝑃 ))π‘˜ (π‘˜ β‰₯ 1) is of different weight and then, by
Theorem 1, 𝜁(𝑃 ) could not satisfy, over Q, an algebraic equation 𝑇 π‘˜ + π‘Žπ‘˜βˆ’1 𝑇 π‘˜βˆ’1 + . . . = 0 meaning
that 𝜁(𝑃 ) is a transcendent number. Since any 𝑃 ∈ ℒ𝒳  ,∞
                                                     π‘–π‘Ÿπ‘Ÿ is homogenous in weight then it follows the
expected result. β–‘

3
    This step and the following ones are not yet been achieved by the implementation in [3].
4
    See also [11] for further information.




                                                              31
Example 1 (irreducible polyzetas, [3]).
                𝑋,≀12
               π’΅π‘–π‘Ÿπ‘Ÿ   = {𝜁(𝑆π‘₯0 π‘₯1 ), 𝜁(𝑆π‘₯20 π‘₯1 ), 𝜁(𝑆π‘₯40 π‘₯1 ), 𝜁(𝑆π‘₯60 π‘₯1 ), 𝜁(𝑆π‘₯0 π‘₯21 π‘₯0 π‘₯41 ), 𝜁(𝑆π‘₯80 π‘₯1 ),
                        𝜁(𝑆π‘₯0 π‘₯21 π‘₯0 π‘₯61 ), 𝜁(𝑆π‘₯10
                                                0 π‘₯1
                                                     ), 𝜁(𝑆π‘₯0 π‘₯31 π‘₯0 π‘₯71 ), 𝜁(𝑆π‘₯0 π‘₯21 π‘₯0 π‘₯81 ), 𝜁(𝑆π‘₯0 π‘₯41 π‘₯0 π‘₯61 )}.
                 π‘Œ,≀12
                π’΅π‘–π‘Ÿπ‘Ÿ   = {𝜁(Σ𝑦2 ), 𝜁(Σ𝑦3 ), 𝜁(Σ𝑦5 ), 𝜁(Σ𝑦7 ), 𝜁(Σ𝑦3 𝑦15 ), 𝜁(Σ𝑦9 ), 𝜁(Σ𝑦3 𝑦17 ),
                         𝜁(Σ𝑦11 ), 𝜁(Σ𝑦2 𝑦19 ), 𝜁(Σ𝑦3 𝑦19 ), 𝜁(Σ𝑦22 𝑦18 )}.

           Example 2 (Rewriting on {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } and {𝑆𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ , irreducible terms).
               Rewriting on {Σ𝑙 }π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 }        Rewriting on {𝑆𝑙 }β„’π‘¦π‘›π‘‹βˆ–π‘‹
             3     Σ𝑦2 𝑦1 β†’ 32 Σ𝑦3                       𝑆π‘₯0 π‘₯21 β†’ 𝑆π‘₯20 π‘₯1
                                           2      2                                                  2 βŠ”βŠ” 2
                            Σ𝑦4    β†’       5 Ξ£ 𝑦2                                𝑆π‘₯30 π‘₯1     β†’       5 𝑆π‘₯0 π‘₯1
                                            3      2                                                 1 βŠ”βŠ” 2
               4        Σ𝑦3 𝑦1     β†’       10 Σ𝑦2                                𝑆π‘₯20 π‘₯21    β†’       10 𝑆π‘₯0 π‘₯1
                                           2      2                                                  2 βŠ”βŠ” 2
                        Σ𝑦2 𝑦12    β†’       3 Ξ£ 𝑦2                                𝑆π‘₯0 π‘₯31     β†’       5 𝑆π‘₯0 π‘₯1
                        Σ𝑦3 𝑦2     β†’ 3Σ𝑦3 Σ𝑦2 βˆ’ 5Σ𝑦5                             𝑆π‘₯30 π‘₯21    β†’      βˆ’π‘†π‘₯20 π‘₯1 𝑆π‘₯0 π‘₯1 + 2𝑆π‘₯40 π‘₯1
                        Σ𝑦4 𝑦1     β†’ βˆ’Ξ£π‘¦3 Σ𝑦2 + 52 Σ𝑦5                     𝑆π‘₯20 π‘₯1 π‘₯0 π‘₯1     β†’      βˆ’ 23 𝑆π‘₯40 π‘₯1 + 𝑆π‘₯20 π‘₯1 𝑆π‘₯0 π‘₯1
               5        Σ𝑦22 𝑦1    β†’ 32 Σ𝑦3 Σ𝑦2 βˆ’ 25
                                                   12 Σ𝑦5                       𝑆π‘₯20 π‘₯31     β†’      βˆ’π‘†π‘₯20 π‘₯1 𝑆π‘₯0 π‘₯1 + 2𝑆π‘₯40 π‘₯1
                                       5                                                            1
                        Σ𝑦3 𝑦12    β†’ 12 Σ𝑦5                                𝑆π‘₯0 π‘₯1 π‘₯0 π‘₯21     β†’      2 𝑆π‘₯40 π‘₯1
                        Σ𝑦2 𝑦13    β†’ 14 Σ𝑦3 Σ𝑦2 + 54 Σ𝑦5                        𝑆π‘₯0 π‘₯41      β†’      𝑆π‘₯40 π‘₯1
                                           8      3                                                 8 βŠ”βŠ” 3
                            Σ𝑦6    β†’      35 Σ𝑦2                                 𝑆π‘₯50 π‘₯1     β†’      35 𝑆π‘₯0 π‘₯1
                                                    4                                               6 βŠ”βŠ” 3       1 βŠ”βŠ” 2
                        Σ𝑦4 𝑦2     β†’      Σ𝑦3 2 βˆ’ 21   Ξ£ 𝑦2 3                    𝑆π‘₯40 π‘₯21    β†’      35 𝑆π‘₯0 π‘₯1 βˆ’ 2 𝑆π‘₯20 π‘₯1
                                          2      3    1      2                                       4    βŠ”βŠ” 3
                        Σ𝑦5 𝑦1     β†’      7 Ξ£ 𝑦2 βˆ’ 2 Ξ£ 𝑦3                  𝑆π‘₯30 π‘₯1 π‘₯0 π‘₯1     β†’      105 𝑆π‘₯0 π‘₯1
                                             17                                                     23 βŠ”βŠ” 3       βŠ”βŠ” 2
                      Σ𝑦3 𝑦1 𝑦2    β†’      βˆ’ 30  Σ𝑦2 3 + 94 Σ𝑦3 2                 𝑆π‘₯30 π‘₯31    β†’      70 𝑆π‘₯0 π‘₯1 βˆ’ 𝑆π‘₯20 π‘₯1
                                                      9                                              2    βŠ”βŠ” 3
                      Σ𝑦3 𝑦2 𝑦1    β†’      3Σ𝑦3 2 βˆ’ 10    Σ𝑦2 3             𝑆π‘₯20 π‘₯1 π‘₯0 π‘₯21    β†’      105 𝑆π‘₯0 π‘₯1
                                           3           3                                               89 βŠ”βŠ” 3          βŠ”βŠ” 2
               6        Σ𝑦4 𝑦12    β†’              3
                                          10 Σ𝑦2 βˆ’ 4 Σ𝑦3
                                                              2            𝑆π‘₯20 π‘₯21 π‘₯0 π‘₯1    β†’      βˆ’ 210 𝑆π‘₯0 π‘₯1 + 32 𝑆π‘₯2 π‘₯
                                                                                                                          0 1
                                          11      3    1      2                                     6 βŠ”βŠ” 3       1 βŠ”βŠ” 2
                        Σ𝑦22 𝑦12   β†’      63 Σ𝑦2 βˆ’ 4 Σ𝑦3                         𝑆π‘₯20 π‘₯41    β†’      35 𝑆π‘₯  π‘₯
                                                                                                          0 1  βˆ’  𝑆   2
                                                                                                                 2 π‘₯0 π‘₯1
                                           1      3                                                 8 βŠ”βŠ” 3        βŠ”βŠ” 2
                        Σ𝑦3 𝑦13    β†’      21 Σ𝑦2                           𝑆π‘₯0 π‘₯1 π‘₯0 π‘₯31     β†’      21 𝑆π‘₯0 π‘₯1 βˆ’ 𝑆π‘₯20 π‘₯1
                                          17      3     3      2                                    8 βŠ”βŠ” 3
                        Σ𝑦2 𝑦14    β†’      50 Σ𝑦2 + 16 Σ𝑦3                        𝑆π‘₯0 π‘₯51     β†’      35 𝑆π‘₯0 π‘₯1


                ℒ𝑋,≀12
                 π‘–π‘Ÿπ‘Ÿ   = {𝑆π‘₯0 π‘₯1 , 𝑆π‘₯20 π‘₯1 , 𝑆π‘₯40 π‘₯1 , 𝑆π‘₯60 π‘₯1 , 𝑆π‘₯0 π‘₯21 π‘₯0 π‘₯41 , 𝑆π‘₯80 π‘₯1 ,
                                   𝑆π‘₯0 π‘₯21 π‘₯0 π‘₯61 , 𝑆π‘₯10
                                                      0 π‘₯1
                                                           , 𝑆π‘₯0 π‘₯31 π‘₯0 π‘₯71 , 𝑆π‘₯0 π‘₯21 π‘₯0 π‘₯81 , 𝑆π‘₯0 π‘₯41 π‘₯0 π‘₯61 }.
                    π‘Œ,≀12
                   β„’π‘–π‘Ÿπ‘Ÿ      = {Σ𝑦2 , Σ𝑦3 , Σ𝑦5 , Σ𝑦7 , Σ𝑦3 𝑦15 , Σ𝑦9 , Σ𝑦3 𝑦17 , Σ𝑦11 , Σ𝑦2 𝑦19 , Σ𝑦3 𝑦19 , Σ𝑦22 𝑦18 }.



3. Conclusion
Thanks to a Abel like theorem and the equation bridging the algebraic structures of the Q-algebra 𝒡
generated by the polyzetas [5], the algorithm LocalCoordinateIdentification provides the algebraic
relations5 among the local coordinates, of second kind on the groups of group-like series, of the
noncommutative series π‘βŠ”βŠ” (i.e. {𝜁(𝑆𝑙 )}π‘™βˆˆβ„’π‘¦π‘›π‘‹βˆ–π‘‹ ) and 𝑍 (i.e. {𝜁(Σ𝑙 )}π‘™βˆˆβ„’π‘¦π‘›π‘Œ βˆ–{𝑦1 } ). These relations
                                                                                          𝒳 ,∞
constitute two confluent rewriting systems in which the irreducible terms, belonging to π’΅π‘–π‘Ÿπ‘Ÿ   , represent
the algebraic generators for 𝒡 and, on the other hand, the βŠ”βŠ” -ideal ℛ𝑋 and the -ideal β„›π‘Œ represent
the kernels of the 𝜁 polymorphism (Proposition 1). These ideals are generated by the polynomials, totally
ordered and homogenous in weight, {𝑄𝑙 }π‘™βˆˆβ„’π‘¦π‘›π’³ βˆ–gDIV and are interpreted as the confluent rewriting
systems in which the irreducible terms belong to ℒ𝒳   ,∞                                 𝒳
                                                    π‘–π‘Ÿπ‘Ÿ and, in each rewriting rule of β„›π‘–π‘Ÿπ‘Ÿ , the left side
5
    These are different from those among {𝜁(𝑙)}π‘™βˆˆβ„’π‘¦π‘›π’³ βˆ–gDIV obtained by β€œdouble shuffle relations” [8], for which Conjecture 1
    holds, up to weight 10.




                                                                        32
is the leading monomial of 𝑄𝑙 , 𝑙 ∈ ℒ𝑦𝑛𝒳 βˆ– gDIV and is transcendent over Q[ℒ𝒳            ,∞
                                                                                       π‘–π‘Ÿπ‘Ÿ ] while the right
side is canonically represented on Q[ℒ𝒳  ,∞                         𝒳 ,∞
                                       π‘–π‘Ÿπ‘Ÿ ]. It follows that 𝜁(Q[β„’π‘–π‘Ÿπ‘Ÿ ]), i.e. 𝒡, as being isomorphic to
Q1𝑋 * βŠ• π‘₯0 QβŸ¨π‘‹βŸ©π‘₯1 /ℛ𝑋 and to Q1π‘Œ * βŠ• (π‘Œ βˆ– {𝑦1 })QβŸ¨π‘Œ ⟩/β„›π‘Œ , is Q-free and graded (Theorem 1) and
then irreducible polyzetas, being Q-algebraic independent, are transcendent numbers (Corollary 1). By
                                                                              𝒳 ,≀12
these results, up to weight 12, Conjecture 1 holds (see also6 [7, 12]), i.e. π’΅π‘–π‘Ÿπ‘Ÿ    is Q-algebraically free
(Example 2).


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[11] V. Hoang Ngoc Minh.– On the Algebraic Bases of Polyzetas, in submission.
[12] M. Kaneko, M. Noro, and K. Tsurumaki.– On a conjecture for the dimension of the space of the
    multiple zeta values, IMA Volumes in Mathematics and its Applications 148, Springer, New York,
    2008, pp. 47-58.
[13] D. Zagier.– Values of zeta functions and their applications, in β€œFirst European Congress of Mathe-
    matics", vol. 2, BirkhΓ€user, pp. 497-512, (1994).




6
    All these implementations base on the β€œdouble shuffle relations" and provide linear relations.




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