<<< mml $\begin{array}{c}x-\frac{a}{b}x\\ x-\frac{1}{b}x\\ x-\frac{1}{2}x\\ x-\frac{1^2}{z}x\\ x-\frac{z}{1^2}x\end{array}$ >>> native [ EArray [ AlignCenter ] [ [ [ EGrouped [ EIdentifier "x" , ESymbol Bin "-" , EFraction NormalFrac (EIdentifier "a") (EIdentifier "b") , EIdentifier "x" ] ] ] , [ [ EGrouped [ EIdentifier "x" , ESymbol Bin "-" , EFraction NormalFrac (ENumber "1") (EIdentifier "b") , EIdentifier "x" ] ] ] , [ [ EGrouped [ EIdentifier "x" , ESymbol Bin "-" , EFraction NormalFrac (ENumber "1") (ENumber "2") , EIdentifier "x" ] ] ] , [ [ EGrouped [ EIdentifier "x" , ESymbol Bin "-" , EFraction NormalFrac (ESuper (ENumber "1") (ENumber "2")) (EIdentifier "z") , EIdentifier "x" ] ] ] , [ [ EGrouped [ EIdentifier "x" , ESymbol Bin "-" , EFraction NormalFrac (EIdentifier "z") (ESuper (ENumber "1") (ENumber "2")) , EIdentifier "x" ] ] ] ] ]