prefix¶
-
element_index_type
libsemigroups::FroidurePinBase
::
prefix
(element_index_type pos) const¶ Returns the position of the prefix of the element
x
in positionpos
(of the semigroup) of length one less than the length ofx
.The parameter
pos
must be a valid position of an already enumerated element of the semigroup, or a LibsemigroupsException will be thrown.