INF 223, Spring 2019, Tentative plan of Lectures (Status 05.02.2020)






Nr.DateWeekTopicsPages





1.15.01.20 3 - What is Category Theory?
- shift of paradigm
- informal discussion of products, dualization, sums
2.16.01.20 3 - graphs and graph homomorphisms: motivation, examples, definition
- opposite graphs
- discussion of isomorhisms between graphs





3.22.01.20 4 - composition of maps and identity maps
- composition of graph homomorphisms and identity graph homomorphisms
- associativity and identity law of composition
- definition of category
- categories Set and Graph
- a universal definition of isomorphism
4.23.01.20 4 - composition of isomorphisms is isomorphism
- isomorphisms in Set are bijective maps
- isomorphisms in Graph are componentwise bijective graph homomorphisms
- some finite categories
- representation of finite categories by pictorial diagrams
- other categories with sets as objects: Incl, Inj, Par
- Nat and Incl as pre-order categories
- pre-order categories and partial order categories





5.29.01.20 5 - subcategory: examples and definition
- discussion associations in class diagrams
- composition of relations
- category Rel
- association ends and multimaps
6.30.01.20 5 - category Mult
- monoids: examples and definition
- monoid morphisms: examples and definition
- category Mon of monoids





7.05.02.20 6 - inductive definition of lists
- universal property of lists (free monoids)
- functors: motivation, definition
- functors: examples
- product graphs with finite example
8.06.02.20 6 - product categories
- functors preserve isomorphisms
- opposite category and contravariant functors
- identity functors and composition of functors
- categories of categories: Cat, CAT, SET, GRAPH
- pathes: motivation, examples, definition
- path graph and evaluation of paths





9.12.02.20 7 - categorical diagrams: motivation, definition, examples
- commutative diagram: definition and examples
- path categories
- summary of the first lectures about "structures"
- general discussion about models and metamodels
- discussion of a "metamodel" MG of graphs
10.13.02.20 7 - graphs as interpretations of the graph MG in Set
- graph homomorphisms as natural transformations
- definition of natural transformations
- natural transformations: composition and identities
- definition of interpretation categories





11.19.02.20 8 - indexed sets as functor category
- arrow categories
- category of E-graphs
- discussion of arrows between arrows
- path equations, satisfaction of path equations
- model interpretations
- reflexive graphs
12.20.02.20 8 - motivation of "typing" by ER-diagrams and Petri nets
- type graph and typed graphs and their morphisms
- definition slice category
- example typed E-graphs
- indexed vs. typed sets
- equivalence of categories





26.02.20 9 no lecture (Winter holiday)
27.02.20 9 no lecture (Winter holiday)





13.04.03.2010 - equivalence relations and equivalence classes
- quotient sets and natural maps
- unique factorization of maps
- equivalences as abstraction in mathematics
- representatives and normal forms
- quotient path categories
14.05.03.2010 - monomorphisms: definition, examples in Set, Graph, Incl
- epimorphisms: definition, examples in Set, Graph, Incl
- split mono's and epi's
- in Set all epi's are split -> axiom of choice





15.11.03.2011 - initial objects: definition, examples in , Incl, Set, , Mult, Graph
- terminal objects: definition, examples in , Incl, Set, Mult, Graph
16.12.03.2011 - sum: definition, examples in , Incl, Set, Graph
- product: definition, examples in , Incl, Set, Graph





17.18.03.2012 - motivation pullbacks: intersection, inner join, products of typed graphs
- pullbacks: definition, examples in Incl, Set, Graph
- preimages as pullbacks
- equalizers: definition, example in Set
- kernel and graph of a map f:A->B as equalizers
18.19.03.2012 - general construction of pullbacks by products and equalizers
- fibred products
- equalizers are mono
- monics are reflected by pullbacks, coding of monics by pullbacks
- composition of pullbacks is a pullback and decomposition of pullbacks





19.25.03.2013 - motivation pushouts: sharing, decomposition of graphs, rule applications
- pushouts: definition, examples in , Incl, Set, Graph
- coequalizers, general construction of pushouts by sums and coequalizers
- discussion: two lines of constructions
26.03.2013 - definition of diagrams
- cones and limits
- co-cones and colimits
- completeness and co-completeness
- stepwise construction of limits and colimits





01.04.2014 no lecture (buffer/lecture monads?)
02.04.2014 no lecture (buffer/lecture monads?)





08.04.2015 no lecture (Easter Holiday)
09.04.2015 no lecture (Easter Holiday)





20.15.04.2016 - research project: flexible and universal diagrammatic formalism
- categorical sketches: example binary relations
- criticism of sketch approach
21.16.04.2016 - relation = jointly injective/monic
- dualization = jointly surjective/epic (cover), example subclasses
- ER diagrams in DPF
- key = injective map
- composite attributes = products
- formalization of associations: predicate [opp]





22.22.04.2017 - diagrammatic signature: definition and examples
- atomic constraints
- diagrammatic specification
- discussion of two variants of EER models
- semantic interpretations in a "semantic universe" U
- indexed semantics = interpretation categories
- satisfaction of atomic constraints
- specification morphisms: definition and example; category of specifications
23.23.04.2017 - revised type graph for ER diagrams
- semantics-as-instances
- discussion extending type graphs to metamodels
- informal discussion of modelling hierarchies





24.28.04.2018 - typed signatures, typed atomic constraints, typed specifications
- conformant specification
- modelling formalism and modelling hierarchies
25.29.04.2018 - discussion model transformation
- joined modelling formalism - example object-oriented models joined with relational data models
- transformation rules: definition
- model transformation = application of transformation rule = pushout
- example from oo models to relational data models
- discussion control of rule applications: negative application conditions, stratification
- discussion: extracting the constructed relational data model by pullback





26.06.05.2019 TBA
27.07.05.2019 - course summary





20 No more lectures





21 No more lectures





22 No more lectures





03.06.2023 Oral Exam (Plan)
04.06.2023 Oral Exam (Plan)