
% Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
% All rights reserved.
%
% Redistribution and use in source and binary forms, with or without
% modification, are permitted provided that the following conditions are
% met:
%
%     - Redistributions of source code must retain the above copyright
%       notice, this list of conditions and the following disclaimer.
%
%     - Redistributions in binary form must reproduce the above copyright
%       notice, this list of conditions and the following disclaimer in
%       the documentation and/or other materials provided with the
%       distribution.
%
%     - Neither the name of The Numerical ALgorithms Group Ltd. nor the
%       names of its contributors may be used to endorse or promote products
%       derived from this software without specific prior written permission.
%
% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
% IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
% TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
% PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
% OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
% EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
% PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES-- LOSS OF USE, DATA, OR
% PROFITS-- OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
% LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
% NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
% SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


%
% OVAR.htex

The domain \spadtype{OrderedVariableList} provides symbols
which are restricted to a particular list and have a definite
ordering. Those two features are specified by a \spadtype{List Symbol}
object that is the argument to the domain.
\xtc{
This is a sample ordering of three symbols.
}{
\spadcommand{ls:List Symbol:=['x,'a,'z] \bound{ls}}
}
\xtc{
Let's build the domain
}{
\spadcommand{Z:=OVAR ls \bound{Z} \free{ls}}
}
\xtc{
How many variables does it have?
}{
\spadcommand{size()$Z \free{Z}}
}
\xtc{
They are (in the imposed order)
}{
\spadcommand{lv:=[index(i::PI)$Z for i in 1..size()$Z] \bound{lv}\free{Z}}
}
\xtc{
Check that the ordering is right
}{
\spadcommand{sorted?(>,lv) \free{lv}}
}
