 
   July 1, 1994                                                        SIS(1)
 
   stg_extract [-a] [-e] [-c]
 
     Takes the current network and extracts the state transition graph from
     it.
 
     If the -a option is not specified, the values on the latches are taken
     to be the start state, and every state reachable from the start state is
     explored.  This is the normal method of execution.
 
     If the -a option is specified, the state transition graph is extracted
     for all possible start states, provided the number of latches does not
     exceed 16.  This limitation cannot be overridden (there are too many
     states to store).
 
     Extraction of the STG could take an enormous amount of time.  If there
     are more than 16 latches in the network, stg_extract won't attempt to
     extract the STG.  This can be overridden with the -e option.
 
     At the end of stg_extract, a check is done to ensure that the behavior
     of the STG is consistent with that of the logic implementation.  This is
     done with symbolic simulation using BDDs, and could be expensive.
     stg_extract will not do this check for networks with more than 16
     latches or more than 500 transitions unless the -c option is given.
 
     Note: a sweep _i_s _d_o_n_e _o_n _t_h_e _n_e_t_w_o_r_k _b_e_f_o_r_e _t_h_e _S_T_G _i_s _e_x_t_r_a_c_t_e_d.  _T_h_i_s
     _r_e_m_o_v_e_s _l_a_t_c_h_e_s _t_h_a_t _d_o _n_o_t _f_a_n_o_u_t, _s_o _t_h_e _s_w_e_e_p _m_a_k_e_s _t_h_e _e_x_t_r_a_c_t_i_o_n
     _m_o_r_e _e_f_f_i_c_i_e_n_t.
 
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