Bubble

class discopy.cat.Bubble(*args, dom=None, cod=None, name='', method='bubble', **kwargs)

Bases: Box

A bubble is a box with arrow args inside and an optional pair of objects dom and cod.

Parameters:

• args (Arrow) – The arrows inside the bubble.

• dom (T) – The domain of the bubble, default is that of args.

• cod (T) – The codomain of the bubble, default is that of args.

• name (str) – An optional name for the bubble.

• method (str) – The method to call when a functor is applied to it.

• kwargs – Passed to the __init__ of Box.

Raises:

ValueError – When dom is None but all the args have the same dom.

property arg

The arrow inside the bubble if there is exactly one.

property is_id_on_objects

Whether the bubble is identity on objects.