4.1.8.4. causality/Flow¶

class mod.CausalityFlowQuery¶

Representation of a query for a DAG that can be folded back into a given flow. The query is based on a derivation graph and can thus be used for any flow solution from a model based on that derivation graph.

__init__(dg)¶

Construct a query with multiplicity 1 and no borrowing.

Raises: LogicError if dg is None.

dg¶

(Read-only) The underlying derivation graph.

Type: DG

multiplicity¶

Access the multiplicity of the query. It must be at least 1.

Type: int
Raises: (set) LogicError if assigned a number less than 1.

__setitem__(v, count)¶

__setitem__(g, count)

Set the amount of flow allowed to be borrowed at a given vertex. The version taking a graph as argument is equivalent to self[dg.findVertex(g)].

Parameters

v (DGVertex) – a vertex in the derivation graph the query is intended for.
g (Graph) – a graph representing a vertex in the derivation graph the query is intended for.
count (int) – the amount of tokens to allowed to be borrowed in a solution.

__getitem__(v)¶

__getitem__(g)

Parameters

v (DGVertex) – a vertex in the derivation graph the query is intended for.
g (Graph) – a graph representing a vertex in the derivation graph the query is intended for.

Return type

int

Returns

the amount of flow allowed to be borrowed at a given vertex. The version taking a graph as argument is equivalent to self[dg.findVertex(g)].

constrainRouting¶: Access whether transit edges must conform to the routing expressed by the flow. Setting this to false may give results violating flow constraints.