Configuration Encoding

Get started

To get started have a look at kids bike example (examples/kids_bike/model.lp).

Run this by

clingo encoding.lp examples/kids_bike/model.lp --opt-mode=enum 0

The output contains the objects and attribute variables with their values, e.g.

Answer: 1
object((),bike)
object((frontWheel,((),0)),wheel)
object((rearWheel,((),0)),wheel)
val(((),color),yellow)
val(((),wheelSupport),no)
val(((frontWheel,((),0)),size),18)
val(((rearWheel,((),0)),size),18)

For a bit more involved example you can the bike example (has about 600 stable models)

clingo encoding.lp examples/bike/model.lp --opt-mode=enum 0

Clingraph

Visualizing the configuration model

Visualize the configuration models with clingraph using the provided script

./make_plots.sh

The plots will be created in the respective folders with filename clingraph.png.

Visualizing instantiations

Visualize the (partial) instantiations with the file examples/viz_instantiation.lp. You can pipe the stable models to clingraph for this, e.g.

clingo encoding.lp examples/bike/model.lp --outf=2 | clingraph --viz-encoding examples/viz_instantiation.lp  --out=render

Fact format

Configuration model

Types

There is a type named T.

type(T).

Partonomic and connection ports

There is a partonomic/connection part from type S to type T with descriptor D. Its possible multiplicities are given by N1, N2,...

part(S,T,D).
multiplicity(S,T,D,N1)
multiplicity(S,T,D,N2)

connection(S,T,D).
...

Attributes

Type T has an attribute with descriptor D. An attribute can be

• atomic (default, requires a domain of values)
• calculated (requires an aggregate function and path expressions)
  • sum
  • count
  • max
  • min

attr(T,D).
attr(T,D,"count").
attr(T,D,"sum").
attr(T,D,"max").
attr(T,D,"min").

For atomic attributes the domain of attribute D of type T contains value V.

dom(T,D,V)

For calculated attributes D of type T the input to the aggregate function are path expressions P1, P2,... (see below)

path(T,D,P1).
path(T,D,P2).
...

Path expressions

Path expressions are encoded as nested tuple with the first descriptor being the innnermost, e.g., the path (frontWheel,size) is encoded as (size,(frontWheel,()).

Constraints

A constraint is identified by the type T it is attached to, an index I and the kind of constraint. Possible options are

• Table (table)
• Comparison (eq,lt,lte,gt,gte)

For example

constraint((T,I),"table").
constraint((T,I),"eq").

Table constraints

For table constraints the columns are identified by path expressions. Columns Col of constraint (T,I) point to attributes P, where P is a attribute path expressions.

column((T,I),Col,P).

The entry of table constraint (T,I) has value V in column Col and row Row.

entry((T,I),(Col,Row),V).

Comparison constraints

For comparision constraints a left and right path need to be specified. Constraint (T,I) compares attributes P1 and P2 which are both attribute path expressions.

left((T,I),P1).
right((T,I),P2).

Instantiation

Objects

There is an object with name N and type T.

object(N,T)

The name has a nested tuple structure with indices built up from the partonomic port descriptors of the object. The root is always named (). For example object((frontWheel,((),0)),wheel) describes the first frontWheel of the root type wheel.

Valuations

The value of an attribute variable A is V.

val(A,V)

Attribute variables are tuples (O,D) with the object O and the attribute descriptor D.