Constructors

This page contains information about the constructors for the Congruence class.

libsemigroups::Congruence::Congruence(congruence_kind type, FpSemigroup &S)

Construct from kind (left/right/2-sided) and FpSemigroup.

Constructs a Congruence over the FpSemigroup instance S representing a left/right/2-sided congruence according to type.

Complexity

Constant.

Parameters:

• type – whether the congruence is left, right, or 2-sided

• S – a const reference to the finitely presented semigroup over which the congruence is defined.

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

template<typename T>
inline libsemigroups::Congruence::Congruence(congruence_kind type, T const &S)

Construct from kind (left/right/2-sided) and FroidurePin.

Constructs a Congruence over the FroidurePin instance S representing a left/right/2-sided congruence according to type.

Complexity

Linear in the size of S.

Warning

the parameter T const& S is copied, this might be expensive, use a std::shared_ptr to avoid the copy!

Template Parameters:

T – a class derived from FroidurePinBase.

Parameters:

• type – whether the congruence is left, right, or 2-sided

• S – a const reference to the semigroup over which the congruence is defined.

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.

explicit libsemigroups::Congruence::Congruence(congruence_kind type, options::runners opt = options::runners::standard)

Construct from kind (left/right/2-sided) and options.

Constructs an empty instance of an interface to a congruence of type specified by the argument.

See also

set_number_of_generators and add_pair.

Complexity

Constant.

Parameters:

• type – the type of the congruence.

• opt – optionally specify algorithms to be used (defaults to options::runners::standard).

libsemigroups::Congruence::Congruence(congruence_kind type, std::shared_ptr<FroidurePinBase> S)

Construct from kind (left/right/2-sided) and shared pointer to FroidurePin.

Constructs a Congruence over the FroidurePin instance S representing a left/right/2-sided congruence according to type.

Complexity

Constant.

Note

The FroidurePinBase pointed to by S is not copied.

Parameters:

• type – whether the congruence is left, right, or 2-sided

• S – a shared_ptr to the semigroup over which the congruence is defined.

Throws:

(None) – This function guarantees not to throw a LibsemigroupsException.