One proposed mechanism for the hydrolysis of an ester is shown below.

${\mathrm{RCOOR}}^{\mathrm{\prime }}+{\mathrm{H}}_3{\mathrm{O}}^{+}⟶{\mathrm{RCOHOR}}^{\mu +}+{\mathrm{H}}_2\mathrm{O}$

${\mathrm{RCOHOR}}^{\mathrm{\prime }+}+{\mathrm{H}}_2\mathrm{O}⟶\mathrm{RC}\left(\mathrm{OH}\right){\mathrm{OR}}^{\mathrm{\prime }}{\left({\mathrm{OH}}_2\right)}^{+}$

$\mathrm{RC}\left(\mathrm{OH}\right){\mathrm{OR}}^{\mathrm{\prime }}{\left({\mathrm{OH}}_2\right)}^{+}+{\mathrm{H}}_2\mathrm{O}⟶\mathrm{RCOOH}+{\mathrm{R}}^{\mathrm{\prime }}\mathrm{OH}+{\mathrm{H}}_3{\mathrm{O}}^{+}$

Which species is considered an intermediate?