function structure = TF_eqn(bond_number,bonds,direction,cr,args, ...
structure,eqnfile);
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% Version control history
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %% $Id$
% %% $Log$
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if nargin<6
eqnfile = 'stdout';
end;
% Needs port labels etc...
% Effort
if bonds(1,1)==1
oneeqn(bond_number(2),1,bond_number(1),1,cr,args,eqnfile);
else
oneeqn(bond_number(1),1,bond_number(2),1,cr,args,eqnfile);
end;
% Flow
if bonds(1,2)==-1
oneeqn(bond_number(2),-1,bond_number(1),-1,cr,args,eqnfile);
else
oneeqn(bond_number(1),-1,bond_number(2),-1,cr,args,eqnfile);
end;