Expression 45: "S" Subscript, 1 , Baseline equals StartFraction, StartNestedFraction, 1 NestedOver "m" Subscript, 2 , Baseline , EndNestedFraction "K" Subscript, 1 , Baseline plus "K" Subscript, 2 , Baseline plus "m" Subscript, 2 , Baseline "L" Subscript, 1 , Baseline minus "L" Subscript, 2 , Baseline Over "m" Subscript, 2 , Baseline plus StartNestedFraction, 1 NestedOver "m" Subscript, 2 , Baseline , EndNestedFraction , EndFractionS1=1m2K1+K2+m2L1−L2m2+1m2