<<< native [ EGrouped [ ESymbol Bin "-" , EIdentifier "x" ] , EGrouped [ ESymbol Bin "-" , EIdentifier "x" ] , EGrouped [ ESymbol Bin "-" , EIdentifier "x" ] , EGrouped [ ESymbol Bin "-" , EIdentifier "x" ] , ESymbol Bin "-" , EIdentifier "x" , ESymbol Bin "-" , EIdentifier "x" ] >>> eqn {- x} {- x} {- x} {- x} - x - x