cover               package:relations               R Documentation

_C_o_v_e_r_i_n_g _R_e_l_a_t_i_o_n_s

_D_e_s_c_r_i_p_t_i_o_n:

     Compute the covering relation of an endorelation.

_U_s_a_g_e:

     relation_cover(x)

_A_r_g_u_m_e_n_t_s:

       x: an endorelation.

_D_e_t_a_i_l_s:

     Let R be an endorelation with domain (X, X) and P be the
     asymmetric part of R for which x P y iff x R y and not y R x.  (If
     R is a <= order relation, P is the associated strict order.)  We
     say that x is covered by y if x P y and there is no z such that x
     P z and z P y.  One also says that y covers x, or that it is a
     successor of x.

     The covering relation of R consists of all pairs (x, y) for which
     x is covered by y.

