_A_r_e _A_l_l _V_a_l_u_e_s _T_r_u_e?
	
	     all(x)
	
	_D_e_s_c_r_i_p_t_i_o_n:
	
	     all takes a single logical argument x and returns a
	     logical value indicating whether or not all the ele-
	     ments of x are TRUE.
	
	     The value returned is TRUE if all the values in x are
	     TRUE, and FALSE if x contains any FALSE values.  If x
	     consists of a mix of TRUE and NA values, then all
	     returns NA.
	
	_E_x_a_m_p_l_e_s:
	
	     if(all(x>0)) cat("All x values are positive\n")