setstarttime(d_t);

composemap:=lambda(m1,m2)
mn:=emptyset;
for i in m2 do
additem(mn,item(m1,i));
endfor;
mn;
endlambda;

samemap:=lambda(m1,m2)
result:=true;
for j in card(m1) do
if not(equal(item(m1,j),item(m2,j))) then result:=false else noop endif
endfor;
result
endlambda;

alreadyinlist:=lambda(nmap)
res:=false;
for m in listofmaps do
if samemap(nmap, m) then res:=true else noop endif
endfor;
res
endlambda;

indexofmap:=lambda(nmap)
res:=-(0,1);
for m in card(listofmaps) do
if samemap(nmap, item(listofmaps,m)) then res:=m else noop endif
endfor;
res
endlambda;

nameofmap:=lambda(m)
item(namesofmaps,indexofmap(m))
endlambda;

string_n:=prompt("n for Dn");
if tonumber(n,string_n) then
% listofmaps is the list of group elements as mappings, i.e. lists %
listofmaps:=emptyset;
namesofmaps:=emptyset;
% templist is a temporary list which, helps creating the individual group elements %
templist:=emptyset;
for i in n do templist:=insertintolist(templist, 0, i) endfor;
additem(listofmaps, templist);
additem(namesofmaps, "a");
templist:=emptyset;
for i in n do if >(i,0) then additem(templist, i) else noop endif endfor;
additem(templist, 0);
additem(listofmaps, templist);
additem(namesofmaps, "b");
weiter:=true;
while weiter do
weiter:=false;
for map1 in listofmaps do
for map2 in listofmaps do
newmap:=composemap(map1,map2);
if not(alreadyinlist(newmap)) then
additem(listofmaps,newmap);
additem(namesofmaps, concat(nameofmap(map1),nameofmap(map2)));
weiter:=true
else noop endif;
newmap:=composemap(map2,map1);
if not(alreadyinlist(newmap)) then
additem(listofmaps,newmap);
additem(namesofmaps, concat(nameofmap(map2),nameofmap(map1)));
weiter:=true
else noop endif
endfor;
endfor;
endwhile;

writeln(listofmaps);
writeln(namesofmaps);
dn:=addstructure(concat("D",string_n));
for i in card(listofmaps) do addelement(dn, item(namesofmaps,i), *(+(i,1),20), *(+(i,1),20)) endfor;
op:=addtooperations(dn,"*",2,1);
for i1 in card(listofmaps) do for i2 in card(listofmaps) do
setvalue(op, [item(dn,i1),item(dn,i2)], item(dn,indexofmap(composemap(item(listofmaps,i1), item(listofmaps,i2)))))
endfor endfor
else writeln("keine Zahl!"); endif;

writeln(timeasstring(d_t));