All operations defined for incidence structures apply also to near-linear spaces, linear spaces and designs.

NumberOfPoints(D) : Inc -> RngInt

# P : IncPtSet -> RngIntElt

The cardinality v of the point set P of the incidence structure D.

An indexed set E whose elements are the points of the incidence structure D. Note that this creates a standard set and not the point-set of D, in contrast to the function PointSet.

An indexed set E which is the underlying point set of the incidence structure D (i.e. the elements of the set have their "real" types; they are no longer from the category IncPt).

A sequence whose i-th term gives the number of blocks containing the i-th point of the design D.

# B : IncBlkSet -> RngIntElt

The number of blocks b of the incidence structure D with block-set B.

An indexed set containing the blocks of the incidence structure D. In contrast to the function BlockSet, this function returns the collection of blocks of D in the form of a standard set.

BlockSizes(D) : Inc -> [ RngIntElt ]

A sequence whose i-th term gives the number of points in the i-th block of the incidence structure D.

Given a subset S of the point set of an incidence structure D, return the the number of blocks of D that contain S.

The incidence matrix of the incidence structure D.