function M = randpt(alf,minidlen,maxidlen,minnumids,maxnumids)
% outputs a random piecewise-testable language
% by computing a random boolean function of random shuffle ideals
% minidlen = minimal ideal length
% maxidlen = maximal ideal length (smaller => simpler language)
% minnumids = minimal total of ideals in the number boolean expression
% maxnumids) = maximal number of ideals (smaller => simpler language)

S = {};
MM = {};
numids = round(randinseg(minnumids,maxnumids));
for i=1:numids
  %u = get_datum_unique(alf,minidlen,maxidlen,S);
  u = get_datum(alf,minidlen,maxidlen,S);  
  S{i} = u;
  %if isempty(u)
  %  u = '@';
  %end
  fprintf('processing U = %s \n',u);
  %MM{i} = bool2fsa_pt(['(' u ')'],alf);
  MM{i} = shuf2dfsa(u,alf);
end

ii = randperm(numids);
ii=ii(:)';
M = MM{ii(1)};
if flip
  M = negate_fsa(M);
end
for i=ii(2:end)
  Mi = MM{i};
  if flip
    Mi = negate_fsa(Mi);
  end
  if flip
    M = union_dfsa(M,Mi);
  else
    M = intersect_dfsa(M,Mi);
  end
end
return


function r = randinseg(a,b)
r = rand*(b-a) + a;
return

function b=flip
b = round(rand);
return

function x = get_datum(alf,minidlen,maxidlen,PREV)
good = 0;
na = length(alf);
n = round(randinseg(minidlen,maxidlen));
x = alf(ceil(rand(1,n)*na));
return


function x = get_datum_unique(alf,minidlen,maxidlen,PREV)
good = 0;
na = length(alf);
cnt = 1;
while ~good
  n = round(randinseg(minidlen,maxidlen));
  x = alf(ceil(rand(1,n)*na));
  good = isempty(strmatch(x,PREV,'exact'));
  cnt = cnt + 1;
  if cnt > 1000
    'count too high'
    keyboard
  end
end
return