sanity_check

sanity_check(k)

Run structural sanity checks on a planar (or oriented) diagram.

Validates node/endpoint consistency, arc–endpoint counts, twin relationships, Euler characteristic (per component), face coherence, and (for oriented diagrams) endpoint orientations.

Parameters:

k (PlanarDiagram | OrientedPlanarDiagram | list[PlanarDiagram | OrientedPlanarDiagram] | set[PlanarDiagram | OrientedPlanarDiagram] | tuple[PlanarDiagram | OrientedPlanarDiagram, ...]) – A single diagram or a collection of diagrams.

Returns:

True if all checks pass; raises on failure.

Return type:

bool