function[X0,degX0,Y0,degY0,R,degR,S,degS,tm,tn]=dioel(A,degA,B,degB,C,degC)

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   MATLAB function solves the linear Diophantine      %
%   Equations for polynomial matrices. The equation is %
%             AX + BY = C                              %
%   where A,B and C are given polynomial matrices      %
%   The general solution is                            %
%             X = X0 + RT                              %
%             Y = Y0 + ST                              %
%   Where T is an arbitrary matrix of                  %
%   dimensions tm(rows) and tn(columns)                %
%                                                      %
%   call: [X0,degX0,Y0,degY0,R,degR,S,degS,tm,tn]=..   %
%         dioel(A,degA,B,degB,C,degC)                  %
%                                                      %
%   function used: polsize, polmul, polgld, spolcom    %
%                  spoldiv                             % 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   S. Pejchova, Juni 13th 1994           %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   dimensions check                      %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[rA,cA]=polsize(A,degA);
[rB,cB]=polsize(B,degB);
[rC,cC]=polsize(C,degC);

if (rA~=rB)|(rA~=rC)
    error('dioel: Inconsistent dimensions of input matrices');
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   matrix F = [A B]                      %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[F,degF]=spolcom(A,degA,B,degB);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   The greatest common left divisor of A and B %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

mes=0;
[D,degD,U,degU,UI,degUI]=polgld(F,degF,mes);
[rD,cD]=polsize(D,degD);

%   rank F

raF=cD;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   extracting the left divisor D of C    %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[C1,degC1]=spoldiv(D,degD,C,degC);
if isempty(C1)==1
   error('dioel:Matrix D is not a left divisor of C');
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   dimensions set                        %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

raD=cD;                   % rank D

for i=1:cD
    Aux=D(:,(cD-i+1):cD:((cD-i+1)*(degD+1)));
    if Aux==zeros(size(Aux))
       raD=raD-1;
    end
end
Aux=[];
[rC1,cC1]=polsize(C1,degC1);

if (cC1~=cC)|(rC1>rC)
    error('dioel:Error in dimensions of C1');
end

if rC1<rC
   Aux=zeros((rC-rC1),cC1*(degC1+1));
   C1=[C1;Aux];
   rC1=rC;
end

if C1((raD+1):rC1,:)~=zeros((rC1-raD),cC1*(degC1+1))
   error('dioel:D is not a left divisor of C')
end
    [rU,cU]=polsize(U,degU);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Matrix P1 creatig                     %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Aux=[];
P1=[];
for i=1:(degU+1)
    Aux=U(1:cA,((i-1)*cU+1):((i-1)*cU+raF));
    P1=[P1 Aux];
end
degP1=degU;
[rP1,cP1]=polsize(P1,degP1);

if cP1>rA
    error('dioel: Error in column dimension of P1');
end

Aux=[];

if cP1<rA
    Aux=zeros(rP1,(rA-cP1)*(degP1+1));
    P1=[P1 Aux];
    cP1=rA;
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Matrix Q1 creating                   %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Aux=[];
Q1=[];

for i=1:(degU+1)
    Aux=U((cA+1):rU,((i-1)*cU+1):((i-1)*cU+raF));
    Q1=[Q1 Aux];
end
degQ1=degU;
[rQ1,cQ1]=polsize(Q1,degQ1);

if (cQ1>rA)|(rQ1~=cB)
    error('dioel: Error in dimensions of Q1')
end
    Aux=[];
if cQ1<rA
    Aux=zeros(rQ1,(rA-cQ1)*(degQ1+1));
    Q1=[Q1 Aux];
    cQ1=rA;
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Matrix R creating                     %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Aux=[];
R=[];
for i=1:(degU+1)
    Aux=U(1:cA,((i-1)*cU+raF+1):(i*cU));
    R=[R Aux];
end

degR=degU;
[rR,cR]=polsize(R,degR);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Matrix S creating                     %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Aux=[];
S=[];
for i=1:(degU+1)
    Aux=U((cA+1):rU,((i-1)*cU+raF+1):(i*cU));
    S=[S Aux];
end

degS=degU;
[rS,cS]=polsize(S,degS);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Size of matrix T and setting sizes of R and S %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

tm=cR;

if cR==cS
    if (cR>cA+cB)|(cR<cA+cB-raF)
        error('dioel: Error in column dimensions of R and S')
    end

else
    if (cR>cS)&(cR<=(cA+cB))&(cS>=(cA+cB-raF))
        Aux=[];
        Aux=zeros(rS,(degS+1)*(cR-cS));
        S=[S Aux];
        cS=cR;
    else
        if (cS>cR)&(cS<=(cA+cB))&(cR>=(cA+cB-raF))
            Aux=[]
            Aux=zeros(rR,(degR+1)*(cS-cR));
            R=[R Aux];
            cR=cS;
            tm=cR;
        else
            error('dioel: Error in column dimensions of R and S')
        end
    end
end


if isempty(R)==1
    degR=-inf;
end

if isempty(S)==1
    degS=-inf;
end


tn=cC;

if tm==0|((isempty(R))&(isempty(S)))
    tn=0;
end


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Particular solution X0 = P1 * C1      %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[X0,degX0]=polmul(P1,degP1,C1,degC1);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%   Particular solution Y0 = Q1 * C1      %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[Y0,degY0]=polmul(Q1,degQ1,C1,degC1);