Syntax
where B0 is the name of the base being defined, and
The BASE: command is used to define a base, being a
collection of elements (and possibly data carriers). The definition part
consists of the names of the elements and data carriers to form the
base. If the names of any pre-existing bases are included in the
definition part, their constituents are included in the new base B0.
If the base being defined in the naming part also appears in the
definition part, all the elements included in the former definition are
also included in the new definition. Unrecognised quantities are allowed
in the RHS of the definition. This allows semi-recursive base creation,
as in
where B1 does not exist a priori.
The second form of the syntax is used to exclude consituents of
the base constructed so far. See §6.2.3.
are the names of elements and bases.
, ...