<<< mml $\text{Inline double up down arrows, text style, thick line }\Updownarrow \genfrac{}{}{1pt}{}{\sin \theta }{M}\Updownarrow \text{ the end.}$ >>> native [ EText TextNormal "Inline double up down arrows, text style, thick line\160" , EDelimited "" "" [ Left "\8661" , Right (EFraction NormalFrac (EGrouped [ EMathOperator "sin" , ESymbol Ord "\8289" , EIdentifier "\952" ]) (EIdentifier "M")) , Left "\8661" ] , EText TextNormal "\160the end." ]