White and light blue contours present the moment 0 map of the ¹³CO emission at the medium velocities and the C¹⁸O emission, respectively. Color scales present the moment 1 maps of panel a: the observed ¹³CO emission computed with the entire velocity range, same as Fig. 1 left; panel b: Keplerian rotating envelope model; panel c: infalling and rotating envelope model; and panel d: infalling and counter-rotating envelope model in units of km s^-1 in the LSR frame. Blue and red arrows show the directions of the blue- and redshifted outflows. Crosses denote the position of HL Tau. Contour levels are 5%, 10%, 15%, 20%, 35%, 70%, and 90% of the peak intensity in the ¹³CO map, and are 20%, 50%, and 80% of the peak intensity in the C¹⁸O map. The peak intensities are 0.78 and 0.41 Jy Beam^-1 km s^-1, corresponding to 94σ and 52σ, in the ¹³CO and C¹⁸O maps, respectively.