Expression 27: "D" Subscript, 1 , Baseline equals StartFraction, StartNestedFraction, 1 NestedOver "m" Subscript, 2 , Baseline , EndNestedFraction "E" Subscript, 1 , Baseline plus "E" Subscript, 2 , Baseline minus StartNestedFraction, 1 NestedOver "m" Subscript, 1 , Baseline , EndNestedFraction "C" Subscript, 1 , Baseline minus "C" Subscript, 2 , Baseline Over StartNestedFraction, 1 NestedOver "m" Subscript, 2 , Baseline , EndNestedFraction minus StartNestedFraction, 1 NestedOver "m" Subscript, 1 , Baseline , EndNestedFraction , EndFractionD1=1m2E1+E2−1m1C1−C21m2−1m1