-- -*- M2-comint -*- hash: 2262535026686930967

i1 : R = QQ[a..d, MonomialOrder=>GroupRevLex=>2, Global=>false];

i2 : a^-1

      -1
o2 = a

o2 : R

i3 : try c^(-1) else "failed"

o3 = failed

i4 : 
