AC=12>MR\mathrm {AC = 12 > MR}AC=12>MR
AC=15=AR\mathrm {AC = 15 = AR}AC=15=AR
AC=12<MR\mathrm {AC = 12 <MR}AC=12<MR
AC=15=MR\mathrm {AC = 15 = MR}AC=15=MR