%  INTERNAL FUNCTION: change the parameter names from name_chain_state to name(chain,state)
% 
%  ::
% 
%    pname=param_name_to_param_texname(pname,chain_names)
% 
%  Args:
% 
%     - **pname** [char|cellstring: names of the parameters to change
% 
%     - **chain_names** [cellstring]: names of the markov chains
% 
%  Returns:
%     :
% 
%     - **pname** [char|cellstring]: names of the changed parameters
% 
%  See also:
%     - parser.param_texname_to_param_name
% 
%