_O_u_t_e_r _P_r_o_d_u_c_t _o_f _V_e_c_t_o_r_s
	
	     outer(x, y, FUN = "*", ...)
	
	_A_r_g_u_m_e_n_t_s:
	
	           x : a vector.
	
	           y : a vector.
	
	         FUN : a function to use on the outer products, it
	               may be a quoted string.
	
	         ... : optional arguments to be passed to fun.
	
	_D_e_s_c_r_i_p_t_i_o_n:
	
	     The outer product of the vectors x and y is the matrix
	     A with elements A[i, j] = FUN(x[i], y[j], ...).  FUN
	     must be a function which expects at least two arguments
	     and which operates elementwise on arrays.
	
	     This needs to be extended to taking arrays of arbitrary
	     dimension for x and y and returns an array of dimension
	     c(dim(x), dim(y)).
	
	_E_x_a_m_p_l_e_s:
	
	     outer(1:5, 1:5, "+")