algebraixlib.algebras.clans module

This module contains the algebra of clans and related functionality.

A clan is also a set (of relations), and inherits all operations of the algebra of sets. These are provided in sets.

class algebraixlib.algebras.clans.Algebra[source]

Bases: object

Provide the operations and relations that are members of the algebra of clans.

This class contains only static member functions. Its main purpose is to provide a namespace for and highlight the operations and relations that belong to the algebra of clans. All member functions are also available at the enclosing module scope.

static transpose()[source]

Return a clan where all relations have their left and right components swapped.

Returns:The unary extension of transposition from the algebra of relations to the algebra of clans, applied to clan, or Undef() if clan is not a clan.
static compose()[source]

Return the composition of clan1 with clan2.

Returns:The binary extension of composition from the algebra of relations to the algebra of clans, applied to clan1 and clan2, or Undef() if clan1 or clan2 are not clans.
static cross_union()[source]

Return the cross-union of clan1 and clan2.

The cross-union of two clans is a clan that contains the result of unioning every relation from one clan with every relation from the other clan.

Returns:The binary extension of union from the algebra of relations (which inherits it from the algebra of sets) to the algebra of clans applied to clan1 and clan2, or Undef() if clan1 or clan2 are not clans.
static cross_functional_union()[source]

Return the cross-functional union of clan1 and clan2.

The cross-functional union of two clans is the cross-union of these clans, but removing all resulting relations that are not functions.

Returns:The binary extension of the functional union from the algebra of relations to the algebra of clans, applied to clan1 and clan2, or Undef() if clan1 or clan2 are not clans.
static lhs_cross_functional_union()[source]

Return the lhs-cross-functional union (‘left join’) of lhs and rhs.

This operation results in a clan that contains every relation of a cross-functional union, but also contains all relations in lhs that are not already part of one of the resulting relations.

Parameters:lhs – All relations in this clan are guaranteed to be represented in the result.
Returns:The resulting clan or Undef() if lhs or rhs are not clans.
static cross_right_functional_union()[source]

Return the cross-right-functional union of clan1 and clan2.

The cross-right-functional union of two clans is the cross-union of these clans, but removing all resulting relations that are not right-functional.

Returns:The binary extension of the right-functional union from the algebra of relations to the algebra of clans, applied to clan1 and clan2, or Undef() if clan1 or clan2 are not clans.
static cross_intersect()[source]

Return the cross-intersection of clan1 and clan2.

The cross-intersection of two clans is a clan that contains the result of intersecting every relation from one clan with every relation from the other clan.

Returns:The binary extension of intersection from the algebra of relations (which inherits it from the algebra of sets) to the algebra of clans applied to clan1 and clan2, or Undef() if clan1 or clan2 are not clans.
static substrict()[source]

Return the substriction of clan1 and clan2.

The substriction of two clans is a clan that contains all relations from clan1 that are a subset of a relation from clan2.

Returns:The binary extension of substriction from the algebra of sets to the algebra of clans applied to clan1 and clan2, or Undef() if clan1 or clan2 are not clans.
static superstrict()[source]

Return the superstriction of clan1 and clan2.

The superstriction of two clans is a clan that contains all relations from clan1 that are a superset of a relation from clan2.

Returns:The binary extension of superstriction from the algebra of sets to the algebra of clans applied to clan1 and clan2, or Undef() if clan1 or clan2 are not clans.
algebraixlib.algebras.clans.transpose()

Convenience redirection to Algebra.transpose.

algebraixlib.algebras.clans.compose()

Convenience redirection to Algebra.compose.

algebraixlib.algebras.clans.cross_union()

Convenience redirection to Algebra.cross_union.

algebraixlib.algebras.clans.cross_functional_union()

Convenience redirection to Algebra.cross_functional_union.

algebraixlib.algebras.clans.lhs_cross_functional_union()

Convenience redirection to Algebra.lhs_cross_functional_union.

algebraixlib.algebras.clans.cross_right_functional_union()

Convenience redirection to Algebra.cross_right_functional_union.

algebraixlib.algebras.clans.cross_intersect()

Convenience redirection to Algebra.cross_intersect.

algebraixlib.algebras.clans.substrict()

Convenience redirection to Algebra.substrict.

algebraixlib.algebras.clans.superstrict()

Convenience redirection to Algebra.superstrict.

algebraixlib.algebras.clans.get_name() → str[source]

Return the name and ground set of this algebra in string form.

algebraixlib.algebras.clans.get_ground_set() → algebraixlib.structure.Structure[source]

Return the ground set of this algebra.

algebraixlib.algebras.clans.get_absolute_ground_set() → algebraixlib.structure.Structure[source]

Return the absolute ground set of this algebra.

algebraixlib.algebras.clans.is_member(obj: algebraixlib.mathobjects.mathobject.MathObject) → bool[source]

Return whether obj is a member of the ground set of this algebra.

return:True if obj is a clan, False if not.

Note

This function may call get_ground_set() on obj. The result of this operation is cached.

algebraixlib.algebras.clans.is_member_or_undef(obj: algebraixlib.mathobjects.mathobject.MathObject) → bool[source]
Return whether obj is either a member of the ground set of this algebra
or Undef.
Returns:True if obj is either a relation or Undef, False if not.
algebraixlib.algebras.clans.is_absolute_member(obj: algebraixlib.mathobjects.mathobject.MathObject) → bool[source]

Return whether obj is a member of the absolute ground set of this algebra.

return:True if obj is an absolute clan, False if not.

Note

This function may call get_ground_set() on obj. The result of this operation is cached.

algebraixlib.algebras.clans.get_lefts()[source]

Return the set of the left components of all couplets in all relations in clan.

Returns:The union of the left sets of all relations in clan or Undef() if clan is not a clan.
algebraixlib.algebras.clans.get_rights()[source]

Return the set of the right components of all couplets in all relations in clan.

Returns:The union of the right sets of all relations in clan or Undef() if clan is not a clan.
algebraixlib.algebras.clans.is_functional(clan, _checked=True) → bool[source]

Return whether clan is functional.

Returns:True if every relation in clan is functional (is a function), False if not, or Undef() if clan is not a clan.
algebraixlib.algebras.clans.is_right_functional(clan, _checked=True) → bool[source]

Return whether clan is right-functional.

Returns:True if every relation in clan is right-functional, False if not, or Undef() if clan is not a clan.
algebraixlib.algebras.clans.is_regular(clan, _checked=True) → bool[source]

Return whether clan is (left-)regular.

Returns:True if clan is regular, False if not, or Undef() if clan is not a clan.
algebraixlib.algebras.clans.is_right_regular(clan, _checked=True) → bool[source]

Return whether clan is right-regular.

Returns:True if clan is right-regular, False if not, or Undef() if clan is not a clan.
algebraixlib.algebras.clans.is_reflexive(clan, _checked=True) → bool[source]

Return whether clan is reflexive.

Returns:True if every relation in clan is reflexive, False if not, or Undef() if clan is not a clan.
algebraixlib.algebras.clans.is_symmetric(clan, _checked=True) → bool[source]

Return whether clan is symmetric.

Returns:True if every relation in clan is symmetric, False if not, or Undef() if clan is not a clan.
algebraixlib.algebras.clans.is_transitive(clan, _checked=True) → bool[source]

Return whether clan is transitive.

Returns:True if every relation in clan is transitive, False if not, or Undef() if clan is not a clan.
algebraixlib.algebras.clans.project()[source]

Return a clan that contains only the couplets with lefts from clan that match lefts.

Parameters:
  • clan – The source data. Must be a clan.
  • lefts – The names of the left components to match. (If you want to pass in an iterable, you need to prefix it with an asterisk *.)
Returns:

The projection of clan (a clan that contains only couplets with left components as indicated by lefts), or Undef() if clan is not a clan.
algebraixlib.algebras.clans.from_set()[source]

Return a clan where all relations contain a single couplet with the same left component.

Parameters:
  • left – The left component of all couplets in the returned clan.
  • values – The right components of the couplets in the returned clan. (If you want to pass in an iterable, you need to prefix it with an asterisk *.)
Returns:

A clan where every relation consists of a single couplet with a left component of left and a right component from values.
algebraixlib.algebras.clans.from_dict()[source]

Return a clan with a single relation where the couplets are the elements of dict1.

algebraixlib.algebras.clans.diag()[source]

Return a clan diagonal of the arguments.

Parameters:args – Pass in the elements from which the clan diagonal is formed. (If you want to pass in an iterable, you need to prefix it with an asterisk *.)
algebraixlib.algebras.clans.defined_at()[source]

Return the relations of clan that are defined for left.