Exhaustive methylation of a trisaccharide followed by acid hydrolysis yields equimolar quantities of 2,3,4,6-tetra-O-methyl-D-galactose, 2,3,4-tri-O-methyl-D-mannose, and 2,4,6-tri-O-methyl-D-glucose. Treatment of the trisaccharide with beta galactosidase yields D-galactose and a disaccharide. Treatment of this disaccharide with alpha mannosidase yields D-mannose and D-glucose. Draw the structure of the trisaccharide and state its systematic name.