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BEGIN:VEVENT
SUMMARY:Mikhail Zaicev (Moscow State University)
DTSTART;VALUE=DATE-TIME:20201204T110000Z
DTEND;VALUE=DATE-TIME:20201204T120000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/1
DESCRIPTION:Title: Polynomial identities:anomalies of codimension growth\n
by Mikhail Zaicev (Moscow State University) as part of Algebra and Logic S
eminar\n\n\nAbstract\nWe consider numerical invariants associated with pol
ynomial identities of algebras over a field of characteristic zero. Given
an algebra $A$\, one can construct a sequence of non-negative integers ${c
_n(A)}\, n = 1\, 2\, . . .$ \, called the codimensions of $A$\, which is a
n important numerical characteristic of identical relations of $A$. In the
present talk we discuss asymptotic behavior of codimension sequence in di
fferent classes of algebras.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Silvia Boumova (Faculty of Mathematics and Informatics\,University
of Sofia\, and Institute of Mathematics and Informatics\, Bulgarian Acade
my of Sciences)
DTSTART;VALUE=DATE-TIME:20201211T110000Z
DTEND;VALUE=DATE-TIME:20201211T120000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/2
DESCRIPTION:Title: Margarete Wolf\, Symmetric Polynomials in Noncommuting
Variables and Noncommutative Invariant Theory\nby Silvia Boumova (Faculty
of Mathematics and Informatics\,University of Sofia\, and Institute of Mat
hematics and Informatics\, Bulgarian Academy of Sciences) as part of Algeb
ra and Logic Seminar\n\n\nAbstract\nIn 1936 Margarete Caroline Wolfpublish
ed a paper where she proved that the symmetric polynomials in the free ass
ociative algebra form a free subalgebra and described the system of free g
enerators. The purpose of the talk is to present these results from modern
point of view and their relations with other results in the frames of co
mmutative and noncommutative invariant theory.\n\nSatellite talk to the We
binar Women in Mathematics in South-Eastern Europe organized by the Intern
ational Center for Mathematical Sciences - Sofia.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Denjoe O'Connor (School of Theoretical Physics\, Dublin Institute
for Advanced Studies)
DTSTART;VALUE=DATE-TIME:20201215T130000Z
DTEND;VALUE=DATE-TIME:20201215T140000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/3
DESCRIPTION:Title: Hagedorn transitions in Matrix Membranes\nby Denjoe O'C
onnor (School of Theoretical Physics\, Dublin Institute for Advanced Studi
es) as part of Algebra and Logic Seminar\n\n\nAbstract\nMatrix models that
originate in non-commutative deformations of Membranes result in models r
elated to dimensional reductions of higher dimensional Yang-Mills theories
. The confining/deconfining transition becomes a Hagedorn transition in th
is setting and the models are believed to have gravitational duals. I will
discuss recent progress in understanding these models and their physics.\
n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vesselin Drensky (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T075000Z
DTEND;VALUE=DATE-TIME:20201218T082000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/4
DESCRIPTION:Title: New examples of fundamental algebras (joint project wit
h Luisa Carini\, University of Messina\, Italy)\nby Vesselin Drensky (Inst
itute of Mathematics and Informatics) as part of Algebra and Logic Seminar
\n\n\nAbstract\nFundamental algebras are the building blocks used to gener
ate any variety of finite basic rank of associative algebras over a field
of characteristic 0. Our first result describes the fundamental algebras w
hich are tensor products of any number of finite dimensional Grassmann alg
ebras. Then we show that the triangular product of two fundamental algebra
s is again fundamental. The proofs are based on the recent description of
fundamental algebras in the language of cocharacter sequences due to Giamb
runo\, Polcino Milies and Zaicev combined with other techniques from the t
heory of PI-algebras.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vassil Kanev (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T082000Z
DTEND;VALUE=DATE-TIME:20201218T085000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/5
DESCRIPTION:Title: Hurwitz modular varieties parametrizing coverings with
fixed monodromy group\nby Vassil Kanev (Institute of Mathematics and Infor
matics) as part of Algebra and Logic Seminar\n\n\nAbstract\nGiven a projec
tive curve $Y$\, a transitive subgroup G of the symmetric group $S_d$ and
a natural number $n$ the talk is devoted to smooth families of coverings o
f $Y$ of degree $d$ branched in $n$ points whose monodromy group is $G$. T
hese families form a category whose morphisms correspond to the pullback b
y morphisms of the bases of the families. Under certain restrictions on th
e group $G$ we construct a universal family in this category. We discuss h
ow to change the category\, so that the universal family exists without an
y restrictions on $G$.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivan Chipchakov (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T085500Z
DTEND;VALUE=DATE-TIME:20201218T092000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/6
DESCRIPTION:Title: Fields of dimension one\, normal over a global or local
field\nby Ivan Chipchakov (Institute of Mathematics and Informatics) as p
art of Algebra and Logic Seminar\n\n\nAbstract\nLet $E$ be a normal extens
ion of a global or local field $K$. We show that if $K$ is a local field\,
$v$ is its (natural) discrete valuation\, and $q$ is the characteristic o
f the residue field of $(K\, v)$\, then $E$ is a field of dimension $dim(E
) ≤ 1$ if and only if the following conditions hold: for each prime numb
er $p ≠ q$\, $E$ contains as a subfield an unramified $ℤ_p$-extension
$K_p$ of $K$\; the restriction $p ≠ q$ is dropped in case the value grou
p $v’(E)$ is $q$-indivisible\, where $v’$ is the unique\, up-to equiva
lence\, valuation of E extending $v$. When $K$ is a global field and $E/K$
is abelian and tamely ramified\, nontrivial Krull valuations of $E$ are d
iscrete\; also\, $dim(E) ≤ 1$ if and only if $E$ is a nonreal field and
the residue fields of these valuations are algebraically closed. Under the
hypothesis that $K$ is a global field\, $E/K$ is abelian and $dim(E) ≤
1$\, this is used for proving the existence\, for each $n \\in ℕ$\, of n
-variate homogeneous polynomials of degree $n$ with coefficients in $E$\,
which violate the local-to global principle over $E$.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tatiana Gateva-Ivanova (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T092000Z
DTEND;VALUE=DATE-TIME:20201218T095000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/7
DESCRIPTION:Title: Associative algebras and Lie algebras defined by Lyndon
words\nby Tatiana Gateva-Ivanova (Institute of Mathematics and Informatic
s) as part of Algebra and Logic Seminar\n\n\nAbstract\nAssume that $X = {x
1\,…\, xg}$ is a finite alphabet and $\\bf{k}$ is a field. We study the
class $C(X\;W)$ of associative graded $\\bf{k}$-algebras $A$ generated by
$X$ and with a fixed obstructions set $W$ consisting of Lyndon words in t
he alphabet $X$. Important examples are the monomial algebras $A = \\bf{k}
⟨X⟩/(W)$\, where $W$ is an antichain of Lyndon words of arbitrary card
inality and the enveloping algebra $Ug$ of any $X$-generated Lie $\\bf{k}$
-algebra $g = {Lie}(X)=([W])$\, whenever the set of standard bracketings $
[W] = {[w] | w \\in W}$ is a Gröbner-Shirshov Lie basis. We prove that al
l algebras $A$ in $C(X\;W)$ share the same Poincare-Birkhoff-Witt type $\\
bf{k}$-basis built out of the so called Lyndon atoms $N$ (determined uniqu
ely by $W$) but\, in general\, $N$ may be infinite. Moreover\, $A$ has pol
ynomial growth if and only if the set of Lyndon atoms $N$ is finite. In th
is case $A$ has a $\\bf{k}$-basis $N = {l_1^{α1} l_1^{α2}… l_1^{αd}|
α_i ≥ 0\, 1≤ i ≤ d}$\, where $N = {l_1\,…\,l_d}$. Surprisingly\,
in the case when $A$ has polynomial growth its global dimension does not d
epend on the shape of its defining relations but only on the set of obstru
ctions $W$: We prove that if $A$ has polynomial growth of degree $d$ then
$A$ has global dimension $d$ and is standard finitely presented\, with $d-
1 ≤|W|≤ d(d - 1)/2$. We study when the set of standard $[W] = {[w] | w
∊ W}$ is a Gröbner-Shirshov Lie basis. We use our general results to c
lassify the Artin-Schelter regular algebras $A$ generated by two elements\
, with defining relations $[W]$ and global dimension $≤ 7$.\n\nReference
s\n\n[1] Tatiana Gateva-Ivanova\, Algebras defined by Lyndon words and Art
in-Schelter regularity\, To appear in The Transactions AMS arXiv preprint
arXiv:1905.11281\n(2019).\n\n[2] Tatiana Gateva-Ivanova\, Gunnar Floystad\
, Monomial algebras defined by Lyndon words\, Journal of Algebra 403 (2014
)\, 470{496.\n\n[3] Tatiana Gateva-Ivanova\, Quadratic algebras\, Yang-Bax
ter equation\, and Artin-Schelter regularity\, Advances in Mathematics 230
(2012)\, 2152{2175.\n\n[4] Tatiana Gateva-Ivanova\, Global dimension of a
ssociative algebras\, Applied Algebra\, Algebraic Algorithms and Error-Cor
recting Codes\, Lecture Notes in Computer Science\, 357 (1989)\, 213-229.\
n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jörg Koppitz (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T095500Z
DTEND;VALUE=DATE-TIME:20201218T101500Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/8
DESCRIPTION:Title: The generators of the semigroup of all transformations
preserving a crown\nby Jörg Koppitz (Institute of Mathematics and Informa
tics) as part of Algebra and Logic Seminar\n\n\nAbstract\nIn this presenta
tion\, we will give a survey about the status of the study of monoids of t
ransformations preserving a fence and a crown\, respectively. In particula
r\, we will consider the monoid of automorphisms preserving fence and crow
n\, respectively. Finally we will give an idea of the current status of st
udy of the rank of the monoid of all partial transformations preserving a
finite crown.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitrinka Vladeva (University of Forestry\, Sofia)
DTSTART;VALUE=DATE-TIME:20201218T101500Z
DTEND;VALUE=DATE-TIME:20201218T103000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/9
DESCRIPTION:Title: Derivations of skew Ore polynomial semirings\nby Dimitr
inka Vladeva (University of Forestry\, Sofia) as part of Algebra and Logic
Seminar\n\n\nAbstract\nIn this project we investigate derivations in the
semiring of skew Ore polynomials over an additively idempotent semiring. W
e show that multiplying each polynomial by $x$ on left is a derivation and
construct commutative idempotent semiring consisting of derivations of a
skew polynomial semiring. We introduce hereditary derivations and generali
zed hereditary derivations defined as derivations acting only over the coe
fficients of the polynomial and also construct an $S$-derivation in the cl
assical sense of Jacobson. Finally we give a description of the derivation
s in a skew polynomial semiring $S[x]$\, assuming that $S$ is an additivel
y idempotent semiring and show that an arbitrary derivation can be represe
nted by a generalized hereditary derivation and an $S$-derivation.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vladimir S. Gerdjikov (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T110000Z
DTEND;VALUE=DATE-TIME:20201218T113000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/10
DESCRIPTION:Title: Recursion operators and the hierarchies of MKdV equatio
ns related to $D_4^{(1)}$\, $D_4^{(2)}$ and $D_4^{(3)}$ Kac-Moody algebras
\nby Vladimir S. Gerdjikov (Institute of Mathematics and Informatics) as p
art of Algebra and Logic Seminar\n\n\nAbstract\nReference:\n\nV. S. Gerdji
kov\, A.A. Stefanov\, I. D. Iliev\, G. P. Boyadjiev et al. Recursion ope
rators and the hierarchies of MKdV equations related to $D_4^{(1)}$\, $D_
4^{(2)}$ and $D_4^{(3)}$ Kac-Moody algebras. \nTheoretical and Mathematic
al Physics\, 204 (3): 1110–1129 (2020)\, ArXiv:2006.16323 [nlin.SI]\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elitza Hristova (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T113000Z
DTEND;VALUE=DATE-TIME:20201218T115000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/11
DESCRIPTION:Title: Regularity of algebras of $O(n)$-invariants using Hilbe
rt series\nby Elitza Hristova (Institute of Mathematics and Informatics) a
s part of Algebra and Logic Seminar\n\n\nAbstract\nLet $W$ be a polynomial
representation of the complex general linear group $GL(n)$. In this talk\
, we discuss the question when the algebra of invariants $ℂ[W]^{O(n)}$ i
s regular\, i.e. isomorphic to a polynomial algebra. For $n=2$\, we give a
list of polynomial $GL(2)$-representations\, so that if $ℂ[W]^{O(2)}$ i
s regular\, then up to an $O(2)$-isomorphism $W$ is in this list. For gene
ral $n$\, we prove regularity in particular cases. The talk is based on a
joint work with Vesselin Drensky.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Veselin Filev (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T115500Z
DTEND;VALUE=DATE-TIME:20201218T122500Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/12
DESCRIPTION:Title: Holographic Berkooz-Douglas Matrix Model at Finite Temp
erature\nby Veselin Filev (Institute of Mathematics and Informatics) as pa
rt of Algebra and Logic Seminar\n\n\nAbstract\nI will report on ongoing wo
rk to construct the holographic dual supergravity background of the Berkoo
z-Douglas matrix model at finite temperature.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hristo Iliev (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T122500Z
DTEND;VALUE=DATE-TIME:20201218T124500Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/13
DESCRIPTION:Title: Families of curves on ruled surfaces and applications t
o the Hilbert scheme of curves\nby Hristo Iliev (Institute of Mathematics
and Informatics) as part of Algebra and Logic Seminar\n\nAbstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vilislav Buchackchiev (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T125000Z
DTEND;VALUE=DATE-TIME:20201218T130500Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/14
DESCRIPTION:Title: Forecasting of the Bulgarian House price index using so
me macroeconomic indicators\nby Vilislav Buchackchiev (Institute of Mathem
atics and Informatics) as part of Algebra and Logic Seminar\n\n\nAbstract\
nWith the introduction of IFRS9 accounting standard in 2018 many banks wer
e required to use statistical models for forecasting the liquidation value
s of houses used as collateral for mortgages. The nature of estimation of
the expected credit loss requires the evaluation of levels of House Price
Index from available statistical data which is\, usually\, one year old. S
everal specifications of the models were studied to confirm that HPI is co
rrelated with various indicators\, including RE market demand\, constructi
on industry business cycle and general macroeconomic environment. The gene
ral conclusion was\, however\, that the two most prominent drivers of HPI
remain the interest rates and the internal inertia of the RE market.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimiter Dobrev (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T130500Z
DTEND;VALUE=DATE-TIME:20201218T133500Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/15
DESCRIPTION:Title: Language for Description of Worlds\nby Dimiter Dobrev (
Institute of Mathematics and Informatics) as part of Algebra and Logic Sem
inar\n\n\nAbstract\nWe will reduce the task of creating AI to the task of
finding an appropriate language for description of the world. This will no
t be a programing language because programing languages describe only comp
utable functions\, while our language will describe a somewhat broader cla
ss of functions. Another specificity of this language will be that the des
cription will consist of separate modules. This will enable us look for th
e description of the world automatically such that we discover it module a
fter module. Our approach to the creation of this new language will be to
start with a particular world and write the description of that particular
world. The point is that the language which can describe this particular
world will be appropriate for describing any world.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Valentin Iliev (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T140000Z
DTEND;VALUE=DATE-TIME:20201218T143000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/16
DESCRIPTION:Title: The Uncertainty Principle for Screening Tests\nby Valen
tin Iliev (Institute of Mathematics and Informatics) as part of Algebra an
d Logic Seminar\n\n\nAbstract\nThe aim of this elementary note is to descr
ibe the relation between the conditional probabilities of a false positive
and a false negative screening test. Non-formally\, we can state the main
result of the paper as an Uncertainty Principle: In general\, if one has
better knowledge that the test is really positive (the probability F_+ of
false positive test is small)\, then for one is hard to know that the test
is really negative (the probability F_- of false negative test is large).
And the better one knows that the test is really negative (F_- is small)\
, the harder it is to know that the test is really positive (F_+ is large)
.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Tatyana Ivanova (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T143000Z
DTEND;VALUE=DATE-TIME:20201218T145000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/17
DESCRIPTION:Title: Contact join-semilattices\nby Tatyana Ivanova (Institut
e of Mathematics and Informatics) as part of Algebra and Logic Seminar\n\n
Abstract: TBA\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Roussanka Loukanova (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T145500Z
DTEND;VALUE=DATE-TIME:20201218T151500Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/18
DESCRIPTION:Title: Type-Theory of Parametric Algorithms\nby Roussanka Louk
anova (Institute of Mathematics and Informatics) as part of Algebra and Lo
gic Seminar\n\n\nAbstract\nI shall present a class of Moschovakis type-the
ories of recursion. My focus is on an overview from the perspective of exi
sting and potential applications. I shall point to some of my contribution
s on these topics.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitar Guelev (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T154500Z
DTEND;VALUE=DATE-TIME:20201218T160000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/19
DESCRIPTION:Title: Strategy Profiles and a Vocabulary for Solving Infinite
Concurrent Games with Temporary Coalitions in QCTL*\nby Dimitar Guelev (I
nstitute of Mathematics and Informatics) as part of Algebra and Logic Semi
nar\n\n\nAbstract\nThis is a short version of my seminar talk from October
30. It highlights the key notion and notations proposed in that talk. The
key notion is a straightforward extension of the notion of strategy profi
le for registering varying partitionings of the totality of the players in
to disjoint coalitions. The notation is a vocabulary for the propositional
ly quantified branching time temporal logic QCTL* which augments the encod
ing of strategy profiles into this logic as known from the literature\, in
cluding my previous work\, with symbols for specifying shifting coalition
structure. In this short presentation\, we focus on the notation and sidel
ine the key technical results of the work\, which show that complete infor
mation concurrent multiplayer infinite games with LTL-definable partially
ordered objectives are solvable wrt whatever solution concepts happen to b
e expressible in the proposed vocabulary. That includes temporary coalitio
n generalisations of some established solution concepts. The work is avail
able from the 8th International Workshop on Strategic Reasoning and arXiv.
\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Valentin Goranko (Institute of Mathematics and Informatics)
DTSTART;VALUE=DATE-TIME:20201218T151500Z
DTEND;VALUE=DATE-TIME:20201218T154500Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/20
DESCRIPTION:Title: Rational coordination in Pure Win-Lose Coordination Gam
es\nby Valentin Goranko (Institute of Mathematics and Informatics) as part
of Algebra and Logic Seminar\n\n\nAbstract\nThe main question I will addr
ess is: when and how can rational agents coordinate without any prior comm
unication or conventions? I will consider this question in the abstract fr
amework of multi-player pure coordination games\, where each player has a
number of possible choices\, every choice profile determines a unique outc
ome\, and in every outcome all players have identical payoffs\, `win’ or
`lose’. \n\nI will formally introduce pure win/lose coordination games
and will present and discuss a hierarchy of ‘rationality principles' tha
t can be applied by rational players in such games to determine their choi
ces of action. Then I will compare the strength of some of these principle
s in terms of the classes of coordination games that can be solved by them
by using only pure reasoning\, without any preplay communication and conv
entions. I will argue that the boundaries between pure rationality princip
les and other rational decision methods used for solving coordination game
s are quite debatable and there is apparently no clear distinction between
these. \n\nLastly\, time permitting\, I will discuss briefly how pure coo
rdination games can be solved with the use of `structural’ conventions (
only based on structural properties of the games)\, agreed in a preplay co
mmunication\, and will describe precisely the scope of purely rational coo
rdination.\n\nThe talk is based on this recent joint paper with Antti Kuus
isto and Raine Rönnholm:\nhttps://academic.oup.com/logcom/article/30/6/11
83/5869758?guestAccessKey=374b9c38-2900-4302-\n91c6-8c8c1eac6ac4.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitrinka Vladeva (University of Forestry\, Sofia)
DTSTART;VALUE=DATE-TIME:20210108T110000Z
DTEND;VALUE=DATE-TIME:20210108T120000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/21
DESCRIPTION:Title: Derivations in matrix semirings\nby Dimitrinka Vladeva
(University of Forestry\, Sofia) as part of Algebra and Logic Seminar\n\n\
nAbstract\nIn the first part of this topic we give a description of the de
rivations in the semiring $UTM_n(S)$ of upper triangular matrices over an
additively idempotent semiring $S$. We consider the matrices $\\overline{
D}_{k} = E_{11} + \\cdots + E_{kk}$\, $1 \\leq k \\leq n$ and $\\underli
ne{D}_{\\\,m} = E_{n-m+1\\\,n-m+1} + \\cdots + E_{nn}$\, $1 \\leq m \\leq
n$ and prove that $\\delta_k(A) = \\overline{D}_{k}A$ and $d_m(A) = A\\u
nderline{D}_{\\\,m}$\, where\n $A \\in UTM_n(S)$\, are derivations in $UTM
_n(S)$. The set $\\overline{\\mathcal{D}}$ of derivations $\\delta_k$\, $
k = 1\, \\ldots\, n$ and the set $\\underline{\\mathcal{D}}$ of derivatio
ns $d_m$\, $m = 1\, \\ldots\, n$\, are additively and multiplicatively ide
mpotent semirings. Denote by ${\\mathcal{D}}$ the semiring generated by t
he set $\\overline{\\mathcal{D}} \\cup \\underline{\\mathcal{D}}$. For $\\
delta_k + d_m \\in {\\mathcal{D}}$ and $A \\in UTM_n(S)$ we describe the
matrix $(\\delta_k + d_m)(A)$ and prove that $\\delta_kd_m \\in {\\mathcal
{D}}$ if and only $\\delta_k + d_m$ is an identiy map. In ${\\mathcal{D}}$
we construct a basis $\\mathcal{B}$ consisting of derivations $\\delta_1
\, \\delta_2\\\,d_{n-1}\, \\ldots\, \\delta_{n-1}\\\,d_{2}\, d_1$ and\n
$\\delta_1\\\,d_{n-1}$\, $\\delta_2\\\,d_{n-2}$\, $\\\;\\ldots\\\;$\, $\\d
elta_{n-2}\\\,d_2$\, $\\delta_{n-1}\\\,d_1$.\n The main result states that
an arbitrary derivation in the semiring $UTM_n(S)$ is a linear combinatio
n of elements of the basis $\\mathcal{B}$ of the $S$-semimodule $\\mathca
l{D}$ with coefficients from $S$.\n\n\nIn the second part we study the der
ivations in the semiring of $n \\times n$ matrices over additively idempo
tent semiring $S$.\nIt is well-known that if $\\delta : S \\rightarrow S$
is a derivation in semiring $S$ then in the semiring $M_n(S)$ of $n \\time
s n$ matrices over $S$ the map $\\delta_{\\rm her}$ such that $\\delta_{\
\rm her}(A) = (\\delta(a_{ij}))$ for any matrix $A = (a_{ij}) \\in M_n(S)
$ is a derivation. These derivations are used in matrix calculus\, differe
ntial equations\, statistics\, physics and engineering and are called here
ditary derivations. On the other hand\n$S$-derivation in matrix semiring $
M_n(S)$ (in sense of N. Jacobson) is a $S$ - linear map $D : M_n(S) \\righ
tarrow M_n(S)$ such that $D(AB) = AD(B) + D(A)B$ where $A\, B \\in M_n(S)
$. We prove that if $S$ is a commutative additively idempotent semiring an
y $S$-derivation is a hereditary derivation. For a noncommutative semirin
g $S$ is introduced a concept of left (right) Ore elements in $S$. Then
we extend the center $C(S)$ to the semiring $LO(S)$ of left Ore elements o
r to the semiring $RO(S)$ of right Ore elements in $S$. We construct left
(right) derivations in these semirings and generalize the result from the
commutative case.\n\n\nhttps://math.bas.bg/wp-content/uploads/2021/01/Alg
ebra_Logika_seminar_08-01-2021-abstract-EN.pdf\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Martin Tabakov (Institute of Philosophy and Sociology\, Bulg.Acad.
Sci.)
DTSTART;VALUE=DATE-TIME:20210115T080000Z
DTEND;VALUE=DATE-TIME:20210115T083000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/22
DESCRIPTION:Title: Challenges of Contemporary Logic to Philosophy\nby Mart
in Tabakov (Institute of Philosophy and Sociology\, Bulg.Acad. Sci.) as pa
rt of Algebra and Logic Seminar\n\n\nAbstract\nThe development of Logic wi
ll be discussing in the light of the popular conceptions of Philosophy of
science - of Kuhn about the scientific revolutions and Lacatos - about the
proliferation. In my opinion in modern logic there are two revolutions -
the transition from traditional to classical logic and the transition from
classical to non-classical logic. In both revolutions the new paradigm ha
s almost completely replaced the old one. The reason for both revolutions
is that the development of the logical empirical sphere has gone considera
bly ahead of the logical theory. My position is that logic does have „em
pirics‟ and this is basically the language and methods of reasoning in s
cientific theories. Revolution' corresponds to the scale of change and re-
evaluation of values in modern logic\, comparable to important moments in
the development of other fields: quantum mechanics\, the transition from N
ewtonian physics to Einstein's theory of relativity\, non-Euclidean geomet
ry.\n\nThe main problem prior to philosophy of logic\, raised by second re
volution is the proliferation. And respectively the questions about the mo
nism and pluralism of logic. After the second revolution Logic has been su
bdivided into a number of logics\; so which one now is “proper Logic”?
And can we talk about “proper Logic” at all?\n\nIn modern logic the t
erm “philosophical logic” has become established. I will discuss quest
ions “What they call and what must be named with It\, and is it possible
and relevant”. Are there a significant field of study for what there is
no suitable term? Where is this field of study named “philosophical log
ic”\, “Is it a (kind of) logic\, or it is philosophy but not logic? An
d about main reasons for the term – “Scientific and Theoretical”\, a
nd “Social and practical”.\n\nJoint seminar dedicated to the World Log
ic Day with the Seminar of the Department of Mathematical Logic and Its Ap
plications of the Faculty of Mathematics and Informatics\, Sofia Universit
y\, and the Seminar of Logic at the Institute of Philosophy and Sociology\
, Bulgarian Academy of Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Doroteya Angelova (Institute of Philosophy and Sociology\, Bulg.Ac
ad. Sci.)
DTSTART;VALUE=DATE-TIME:20210115T083000Z
DTEND;VALUE=DATE-TIME:20210115T090000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/23
DESCRIPTION:Title: Some Solutions of Sorites Paradoxes\nby Doroteya Angelo
va (Institute of Philosophy and Sociology\, Bulg.Acad. Sci.) as part of Al
gebra and Logic Seminar\n\n\nAbstract\nIn the talk\, I will present the ro
le of some non-classical logics in resolving sorites paradoxes. I will ana
lyze the specific characteristics of these logics\, their advantages and s
hortcomings in regard to the problem of vagueness and respectively I will
give arguments which of them are suitable for overcoming the sorites parad
oxes. I will propose two own approaches through which\, according to me\,
it is possible to interpret and resolve the sorites paradoxes: the first o
ne is heterogeneous and the second one – based on three-valued logic.\n\
nKeywords: sorites paradoxes\, vagueness\, fuzzy relevant logic\, heteroge
neous approach\n\nJoint seminar dedicated to the World Logic Day with the
Seminar of the Department of Mathematical Logic and Its Applications of th
e Faculty of Mathematics and Informatics\, Sofia University\, and the Semi
nar of Logic at the Institute of Philosophy and Sociology\, Bulgarian Acad
emy of Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elena Tsvetkova (Institute of Philosophy and Sociology\, Bulg.Acad
. Sci.)
DTSTART;VALUE=DATE-TIME:20210115T090000Z
DTEND;VALUE=DATE-TIME:20210115T093000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/24
DESCRIPTION:Title: Explanation of the Conversation Implicatures with the G
raded Salience Hypothesis\nby Elena Tsvetkova (Institute of Philosophy and
Sociology\, Bulg.Acad. Sci.) as part of Algebra and Logic Seminar\n\n\nAb
stract\nGrice’s theory of conversational implicature is viewed in this p
aper with an accent to the transition between the literal meaning of an ex
pression and the implicated meaning. Assuming the position expressed in th
e graded salience hypothesis\, it is explained that in some cases the tran
sition from what the speaker says to what he wants the listener to under-s
tand is based on the salient meaning of the used expressions. Special atte
ntion is paid to ex-pressions that have more than one obvious meaning\, in
order to show that even when the con-text plays a role in the understandi
ng of an expression\, this meaning can still be perceived as a result of s
ocio-linguistic conventions.\n\nKeywords: Grice\, pragmatics\, graded sali
ence hypothesis\, conversational implicature.\n\nJoint seminar dedicated t
o the World Logic Day with the Seminar of the Department of Mathematical L
ogic and Its Applications of the Faculty of Mathematics and Informatics\,
Sofia University\, and the Seminar of Logic at the Institute of Philosophy
and Sociology\, Bulgarian Academy of Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rosen Lutskanov (Institute of Philosophy and Sociology\, Bulg.Acad
. Sci.)
DTSTART;VALUE=DATE-TIME:20210115T094000Z
DTEND;VALUE=DATE-TIME:20210115T101000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/25
DESCRIPTION:Title: Binary Decision Diagrams for Rational Choice\nby Rosen
Lutskanov (Institute of Philosophy and Sociology\, Bulg.Acad. Sci.) as par
t of Algebra and Logic Seminar\n\n\nAbstract\nRational choice theory is bu
ilt on three fundamental insights: 1. rational choice is (expected) utilit
y maximization\; 2. utilities allow the measurement of preferences on ordi
nal scale\, hence can be represented by weak orders\; 3. preference relati
ons can be generated from axiomatically defined classes of choice operator
s. In the last 60 years enormous amount of axiomatizations of rational cho
ice were presented\, but virtually all of them (a) turn out to be incompat
ible with robust intuitions concerning the meaning of “rational choice
”\; (b) fall prey to counterexamples which show that these definitions a
re not extensionally correct. The present approach proposes to dispense wi
th the received view (“choice is rational when it generates an ordering
of alternatives”) and sketches and alternative account (“choice is rat
ional when the choice procedure fits the choice setting”). It is based o
n a re-interpretation of binary decision diagrams – rooted directed acyc
lic graphs representing Boolean functions (by substituting the labels “t
rue”/“false” with “chosen”/”rejected”). It is shown that thi
s analogy sheds light on some idealizations left implicit by the classic a
pproach.\n\nJoint seminar dedicated to the World Logic Day with the Semina
r of the Department of Mathematical Logic and Its Applications of the Facu
lty of Mathematics and Informatics\, Sofia University\, and the Seminar of
Logic at the Institute of Philosophy and Sociology\, Bulgarian Academy of
Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Alexandra Soskova (Faculty of Mathematics and Informatics\, Sofia
University)
DTSTART;VALUE=DATE-TIME:20210115T101000Z
DTEND;VALUE=DATE-TIME:20210115T104000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/26
DESCRIPTION:Title: Effective Coding and Decoding in Classes of Structures\
nby Alexandra Soskova (Faculty of Mathematics and Informatics\, Sofia Univ
ersity) as part of Algebra and Logic Seminar\n\n\nAbstract\nFriedman and S
tanley introduced Borel embeddings as a way of comparing classi\ncation\np
roblems for di\nerent classes of structures. Many Borel embeddings are act
ually Turing\ncomputable. The e\nective decoding is given by a uniform e\n
ective interpretation. Part\nof the e\nective interpretation is Medvedev r
eduction. The class of undirected graphs and\nthe class of linear ordering
s both lie on top under Turing computable embeddings. We\ngive examples of
graphs that are not Medvedev reducible to any linear ordering\, or to the
\njump of any linear ordering. For any graph there is a linear ordering\,
that the graph is\nMedvedev reducible to the second jump of the linear ord
ering. For the Turing computable\nembedding $L$ of Friedman and Stanley of
directed graphs in linear orderings. We show\nthat there do not exist $L_
{w_1w}$-formulas that uniformly interpret the input graph $G$ in the outpu
t linear ordering $L(G)$. This is joint work with Knight\, and Vatev.\n\nW
e have also one positive result -- we prove that the class of fields is un
iformly effectively interpreted without parameters in the class of Heisenb
erg groups. The second part is a joint work with Alvir\, Calvert\, Goodman
\, Harizanov\, Knight\, Miller\, Morozov\, and\nWeisshaar.\n\nJoint semina
r dedicated to the World Logic Day with the Seminar of the Department of M
athematical Logic and Its Applications of the Faculty of Mathematics and I
nformatics\, Sofia University\, and the Seminar of Logic at the Institute
of Philosophy and Sociology\, Bulgarian Academy of Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Jean-Yves Beziau
DTSTART;VALUE=DATE-TIME:20210115T112500Z
DTEND;VALUE=DATE-TIME:20210115T114000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/27
DESCRIPTION:Title: Official Address\nby Jean-Yves Beziau as part of Algebr
a and Logic Seminar\n\n\nAbstract\nJean-Yves Beziau is the creator of the
World Logic Day and Editor-in-Chief of Logica Universalis.\n\nJean-Yves Be
ziau is the creator of the World Logic Day and Editor-in-Chief of Logica U
niversalis.\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitar Vakarelov (Faculty of Mathematics and Informatics\, Sofia
University)
DTSTART;VALUE=DATE-TIME:20210115T114000Z
DTEND;VALUE=DATE-TIME:20210115T124000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/28
DESCRIPTION:Title: Point-free Theories of Space and Time\nby Dimitar Vakar
elov (Faculty of Mathematics and Informatics\, Sofia University) as part o
f Algebra and Logic Seminar\n\n\nAbstract\nTo the question ”What is spac
e” mathematicians immediately answer: this is what studies geometry\, on
e of the oldest branches of mathematics. Unfortunately\, mathematics does
not have such a branch dedicated to time. Time and space are also basic co
ncepts of physics\, but as a rule physicists borrow their mathematical for
malisms from mathematics. Modern physics has come to the conclusion that s
pace and time must be considered as aspects of a unified theory\, which is
briefly called ”space-time”. But till now physicists still are not gi
ven a definition of time\, rather they say how it is measured\, and time i
s appearing just as a numerical parameter in the basic equations of the th
eory. There has been a heated debate over the nature of space and time sin
ce the time of Newton and Leibniz. Newton defends the so-called ”absolut
e theory of space and time”: ”space” is a container in which the exi
sting things are located\, and ”time” is something that ”flows” an
d is independent of space and material things. Leibniz is the founder of t
he so-called ”relational theory of space and time” according to which
absolute space and time are fictions that have no independent existence: i
n reality there are only things that are in different spatial and temporal
relations. In the early 20th century\, a successor to Leibniz’s ideas w
as Alfred North Whitehead\, who argued that the theory of space and time s
hould be built on a point-free basis. What does this mean. According to th
e Euclidean tradition\, the points of space (as well as the lines and plan
es) are the basic primary concepts that lie in the axiomatization of geome
try. But they do not have an independent existence in reality and are conv
enient fictions. The situation is similar to the points of time (moments)\
, which means that the foundations of a unified theory of space and time m
ust be based on more realistic concepts. This does not mean that the notio
ns of space point and time moment should be disregarded - they should be i
ntroduced later on the base of the primitive notions of the theory. The po
int-free approach to the theory of space and time is quite important from
the point of view of physics: if a given theory is intended to describe re
ality\, its basic concepts should correspond to some things of reality. Th
e first steps in constructing a point-free theory of space were made by Wh
itehead\, De Laguna\, and Tarski\, and this theory is now well known as th
e ”region-based theory of space”\, which is point-free and is based on
the term ”region” as an analogue of a physical body plus some simple
relations between regions\, such as ”part-of” and ”contact”. Howev
er\, a satisfactory point-free axiomatic theory of a unified theory of spa
ce-time does not yet exist. The first steps in this direction were made by
the author of this lecture and its purpose is to tell about one of these
attempts.\n\nThe full text on which the lecture is based can be seen here:
arXiv:2004.14755v2 [math.LO] 30 May 2020.\n\nPublished version: Journal o
f Applied Logics - IfCoLog Journal of Logics and their Applications\, Vol.
7 No. 6\, 2020\, 1243-1321.\n\nAn advice to the interested listeners of t
he lecture is to see the informal Introduction of the above mentioned text
.\n\nJoint seminar dedicated to the World Logic Day with the Seminar of th
e Department of Mathematical Logic and Its Applications of the Faculty of
Mathematics and Informatics\, Sofia University\, and the Seminar of Logic
at the Institute of Philosophy and Sociology\, Bulgarian Academy of Scienc
es\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Vesselin Drensky (Institute of Mathematics and Informatics\, Bulg.
Acad. Sci.)
DTSTART;VALUE=DATE-TIME:20210115T125000Z
DTEND;VALUE=DATE-TIME:20210115T133000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/29
DESCRIPTION:Title: Computational Complexity and Decision Problems in Algeb
ra\nby Vesselin Drensky (Institute of Mathematics and Informatics\, Bulg.
Acad. Sci.) as part of Algebra and Logic Seminar\n\n\nAbstract\nThe idea o
f the talk is to show on concrete examples how classical problems in algeb
ra and arithmetic can be considered from the point of view of mathematical
logic\, theory of algorithms and computer science. The examples are taken
from classical number theory\, cryptography\, numerical semigroups\, comm
utative and noncommutative ring theory\, finite axiomatization\, the P ver
sus NP problem\, decision problems in the theory of groups\, semigroups an
d rings.\n\nJoint seminar dedicated to the World Logic Day with the Semina
r of the Department of Mathematical Logic and Its Applications of the Facu
lty of Mathematics and Informatics\, Sofia University\, and the Seminar of
Logic at the Institute of Philosophy and Sociology\, Bulgarian Academy of
Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Petar Iliev (Institute of Philosophy and Sociology\, Bulg.Acad. Sc
i.)
DTSTART;VALUE=DATE-TIME:20210115T133000Z
DTEND;VALUE=DATE-TIME:20210115T140000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/30
DESCRIPTION:Title: Why Philosophers and Logicians Should Learn More about
Computational Complexity\nby Petar Iliev (Institute of Philosophy and Soci
ology\, Bulg.Acad. Sci.) as part of Algebra and Logic Seminar\n\n\nAbstrac
t\nOne might be tempted to assume that using computer time and memory as e
fficiently as possible to perform a computational task is something that o
bsessive engineers might find important but is of no philosophical and log
ical relevance. This is going to be a very high-level talk\, dedicated to
a very small number of ideas and concepts that originated in the field of
computational complexity\, whose main purpose is to convince philosophers
and logicians unfamiliar with the area but curious to know more about it t
hat the above assumption is wrong.\n\nJoint seminar dedicated to the World
Logic Day with the Seminar of the Department of Mathematical Logic and It
s Applications of the Faculty of Mathematics and Informatics\, Sofia Unive
rsity\, and the Seminar of Logic at the Institute of Philosophy and Sociol
ogy\, Bulgarian Academy of Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Ivan Chipchakov (Institute of Mathematics and Informatics\, Bulg.
Acad. Sci.)
DTSTART;VALUE=DATE-TIME:20210115T141000Z
DTEND;VALUE=DATE-TIME:20210115T144000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/31
DESCRIPTION:Title: Open Problems on Field Extensions of Finite Transcenden
cy Degree and the PAC Property\nby Ivan Chipchakov (Institute of Mathemati
cs and Informatics\, Bulg. Acad. Sci.) as part of Algebra and Logic Semina
r\n\n\nAbstract\nOne of the major open problems on fields of finite transc
endency degrees over their prime subfields is to understand whether an inf
inite field E of this kind is pseudo algebraically closed (abbr.\, PAC)\,
provided that its absolute Galois group is torsion-free and the Henselian
closures of nontrivial valuations of E are separably closed. The purpose o
f this talk is to exhibit relations between the stated problem and the stu
dy of Diophantine properties of fields of dimension ≤ 1 that are algebra
ic extensions of a global field K. We also present an open question posed
by Koenigsmann. It concerns the structure of absolute Galois groups and th
e elementary characterization of fields by such groups\, an area of common
research interest to field theorists – logicians and algebraists.\n\nJo
int seminar dedicated to the World Logic Day with the Seminar of the Depar
tment of Mathematical Logic and Its Applications of the Faculty of Mathema
tics and Informatics\, Sofia University\, and the Seminar of Logic at the
Institute of Philosophy and Sociology\, Bulgarian Academy of Sciences\n
END:VEVENT
BEGIN:VEVENT
SUMMARY:Dimitar P. Guelev (Institute of Mathematics and Informatics\, Bulg
. Acad. Sci.)
DTSTART;VALUE=DATE-TIME:20210115T144000Z
DTEND;VALUE=DATE-TIME:20210115T151000Z
DTSTAMP;VALUE=DATE-TIME:20210124T143436Z
UID:AlgAndLogic/32
DESCRIPTION:Title: Temporary Coalitions and Preference in Quantified Compu
tation Tree Logic\nby Dimitar P. Guelev (Institute of Mathematics and Info
rmatics\, Bulg. Acad. Sci.) as part of Algebra and Logic Seminar\n\n\nAbst
ract\nTemporal winning conditions appear in both terminating and infinite
games\, with terminating games corresponding to safety and reachability (g
uarantee) conditions\, and arbitrary temporal conditions for non-terminati
ng games. In a multiplayer game\, the latter classes of winning conditions
are natural to drive the players into forming permanent coalitions as the
longevity of a coalition needs to match the duration of the joint agenda.
However\, a lifelong joint agenda is often inconsistent with the ability
of players to change their alliances as soon as they see the benefit of do
ing so. This ability can be regarded as inalienable within the considered
game as long as forbidding players to change sides can be modeled by appro
priately modifying the game. Therefore games with temporal winning conditi
ons need to be studied with the possibility of temporary coalitioning in m
ind. Established logical notations for strategic behaviour such as ATLs (A
lur Henzinger and Kupferman\, 1997\, 2002) and Strategy Logics (Chatterjee
\, Henzinger and Piterman\, 2010\, also Mogavero\, Murano and Vardi\, 2010
) include dedicated constructs which are ‘off-the-shelf’ for permanent
coalitions only.\n\nCoalitions form around concrete local agreements with
each prospective coalition member assessing the prospective coalition wit
h the prospective agreement in mind\, and assuming just rationality on beh
alf of the non-signatories. With temporary coalitions this assessment is d
etermined by the progress on each player's individual objectives that can
be made\, if the local agreement goes ahead. The natural ambiguity of rati
onality and assessment entails that even established solution concepts suc
h as equilibria and domination are liable to spawn multiple new variants y
et another time upon their generalization to temporary coalitions.\n\nIn t
his talk we propose two elements of notation for the handling of solution
concepts with temporary coalitions in Quantified Computation Tree Logic. Q
CTL is now an established intermediate notation for strategic reasoning as
it admits embeddings from systems with more specialised constructs and is
known to have decidable validity and model-checking on trees (French\, 20
01\, 2006). The contributed elements are a propositional vocabulary for te
mporary coalitions and a temporal variant of the binary preference operato
r which can be traced back to the work of Von Wright\, 1963. The latter co
nstruct is not temporary-coalition-specific\, but still necessary for the
handling of multiple objectives.\n\nKeywords: strategic ability\, temporar
y coalitions\, rational synthesis\, preference\, concurrent multiplayer ga
mes\n\nThere is a related paper on arXiv: 2011.03724\n\nJoint seminar dedi
cated to the World Logic Day with the Seminar of the Department of Mathema
tical Logic and Its Applications of the Faculty of Mathematics and Informa
tics\, Sofia University\, and the Seminar of Logic at the Institute of Phi
losophy and Sociology\, Bulgarian Academy of Sciences\n
END:VEVENT
END:VCALENDAR