(6R,7R)-3-[(1-aminotetrazol-5-yl)sulfanylmethyl]-7-[[(2Z)-2-[2-(methylamino)-2-oxoethoxy]imino-2-[2-(tritylamino)-1,3-thiazol-4-yl]acetyl]amino]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid