is_bridge

is_bridge(k, arc_or_endpoint)

Return True if the given arc/endpoint is a bridge (a size-1 arc cut-set).

Parameters:

• k (PlanarDiagram) – Diagram.

• arc_or_endpoint – Either an Endpoint (we test the arc with its twin) or a 2-endpoint container.

Raises:

TypeError – if input is neither an Endpoint nor a 2-endpoint container.

Return type:

bool