This section lists various attributes of lattices which can
be examined and set by the user. This allows low-level control of
information stored in lattices. Note that when an attribute is set,
only minimal testing can be done on the value so if an
incorrect value is set, unpredictable results may occur. Note also
that if an attribute is not set, referring to it in an expression
(using the ` operator)
will not trigger the calculation of it (while intrinsic functions
do); rather an error will ensue. Use the assigned operator
to test whether an attribute is set.
L`Minimum
The attribute for the minimum of a lattice L. If the attribute L`Minimum is examined, either the minimum is known so it is returned or an error results. If the attribute L`Minimum is set by assignment, it must be a positive number equal to the minimum of the lattice. Magma will not check that this is correct since that may be very time-consuming. If the attribute is already set, the new value must be the same as the old value.[Next] [Prev] [Right] [Left] [Up] [Index] [Root]