TracedCategory

class discopy.abc.TracedCategory

Bases: MonoidalCategory, Generic

A traced category is a MonoidalCategory with a method trace for the partial trace of a morphism over some objects.

abstract trace(n=1, left=False)

The trace of a morphism, to be instantiated.

Tracing no object at all is the identity, i.e. the vanishing axiom f.trace(0) == f, see nLab.

Parameters:

• n (int) – The number of objects to trace over.

• left (bool) – Whether to trace the wires on the left or right.

Return type:

C1