# Context Sensitive Grammar for the language \${a^nb^nc^nmid n≥1}\$

I tried many grammars and so far I got this one:

begin{align} &S to aSXY mid abc \ &YX to XY \ &aX to ab \ &bX to bb \ &bY to bc \ &cY to cc end{align}

Is my grammar correct? Is there a simpler one?