is_idempotent

bool libsemigroups::FroidurePinBase::is_idempotent(element_index_type) = 0

Returns true if the element in position pos is an idempotent and false if it is not.

The parameter pos must be a valid position of an element of the semigroup, or a LibsemigroupsException will be thrown. This member function involves fully enumerating the semigroup, if it is not already fully enumerated.