INF 223, Spring 2018, Tentative plan of Lectures (Status 24.04.2018)






Nr.DateWeekTopicsPages





1.16.01.18 3 - What is Category Theory?
- shift of paradigm
- informal discussion of products, dualization, sums
5 - 8
2.18.01.18 3 - graphs and graph homomorphisms: motivation, examples, definition
- opposite graphs
- discussion of isomorhisms between graphs
8 - 12





3.23.01.18 4 - composition of maps and identity maps
- composition of graph homomorphisms and identity graph homomorphisms
- associativity and identity law of composition
- definition of category
12 - 14
4.25.01.18 4 - categories Set and Graph
- a universal definition of isomorphism
- composition of isomorphisms is isomorphism
- isomorphisms in Set are bijective maps
- some finite categories
- representation of finite categories by pictorial diagrams
14 - 16





5.30.01.18 5 - other categories with sets as objects: Incl, Inj, Par
- subcategory: examples and definition
- Nat and Incl as pre-order categories
- discussion associations in class diagrams
- composition of relations
17 - 22
6.01.02.18 5 - category Rel
- association ends and multimaps
- category Mult
- monoids: examples and definition
23 - 27





7.06.02.18 6 - monoid morphisms: examples and definition
- category Mon of monoids
- universal property of lists
- functors: motivation, definition
27 - 29
8.08.02.18 6 - functors: examples
- product categories
- opposite category and contravariant functors
- identity functors and composition of functors
- categories of categories: Cat, CAT, SET, GRAPH
29 - 32





9.13.02.18 7 - pathes: motivation, examples, definition
- path graph and evaluation of paths
- categorical diagrams: motivation, definition, examples
- commutative diagram: definition and examples
- path categories
- summary of the first lectures about "structures"
32 - 33
10.15.02.18 7 - general discussion about models and metamodels
- discussion of a "metamodel" MG of graphs
- 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
- indexed sets as functor category
- arrow categories
- category of E-graphs
35 - 39





11.20.02.18 8 - discussion of arrows between arrows
- path equations, satisfaction of path equations
- model interpretations
- reflexive graphs
- motivation of "typing" by ER-diagrams and Petri nets
- type graph and typed graphs and their morphisms
39 - 42
12.22.02.18 8 - definition slice category
- example typed E-graphs
- indexed vs. typed sets
- equivalence of categories
- equivalence relations and equivalence classes
- quotient sets and natural maps
- unique factorization of maps
43 - 48





13.27.02.18 9 - equivalences as abstraction in mathematics
- representatives and normal forms
- quotient path categories
- monomorphisms: definition, examples in Set, Graph, Incl
48 - 56
14.01.03.18 9 no lecture (illness) 56 - 60





15.06.03.1810 - epimorphisms: definition, examples in Set, Graph, Incl
- split mono's and epi's
- in Set all epi's are split -> axiom of choice
- initial objects: definition, examples in , Incl, Set, , Mult, Graph
- terminal objects: definition, examples in , Incl, Set, Mult, Graph
08.03.1810 - sum: definition, examples in , Incl, Set, Graph
- product: definition, examples in , Incl, Set, Graph





16.13.03.1811 - 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
17.15.03.1811 - 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





18.20.03.1812 - 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
19.22.03.1812 - definition of diagrams
- cones and limits
- co-cones and colimits
- completeness and co-completeness
- stepwise construction of limits and colimits





27.03.1813 no lecture (Easter Holiday)
29.03.1813 no lecture (Maundy Thursday)





03.04.1814 no lecture (conference)
05.04.1814 Additional: lecture about monads





20.10.04.1815 - research project: flexible and universal diagrammatic formalism
- categorical sketches: example binary relations
- criticism of sketch approach
21.12.04.1815 - 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]





22.17.04.1816 - 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
23.19.04.1816 - revised type graph for ER diagrams
- semantics-as-instances
- discussion extending type graphs to metamodels
- informal discussion of modelling hierarchies





24.24.04.1817 - typed signatures, typed atomic constraints, typed specifications
- conformant specification
- modelling formalism and modelling hierarchies
26.04.1817 no lecture (institute seminar)





01.05.1818 no lecture (Labor Day)
25.03.05.1818 - 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





26.08.05.1819 - course summary
10.05.1819 no lecture ( Ascension Day)





20 No more lectures





21 No more lectures





22 No more lectures





04.06.1523 Oral Exam