<<< native [ EUnder False (EIdentifier "x") (ESymbol Accent "\8412") , ESymbol Rel "\8800" , EUnder False (EIdentifier "x") (ESymbol Accent "\8412") , ESymbol Rel "=" , EUnder False (EIdentifier "x") (ESymbol Accent "\8412") , ESymbol Rel "=" , EUnder False (EIdentifier "x") (ESymbol Accent "\8412") ] >>> tex \underset{\ddddot{}}{x} \neq \underset{\ddddot{}}{x} = \underset{\ddddot{}}{x} = \underset{\ddddot{}}{x}