MAYBE
Time: 0.599

Problem:
 Equations:
  
 TRS:
  pAC(x,0()) -> x
  pAC(minus(x),x) -> 0()
  m(I(),x) -> x
  m(i(x),x) -> I()
  m(x,m(y,z)) -> m(m(x,y),z)
  m(i(x),m(x,y)) -> y
  m(x,I()) -> x
  i(I()) -> I()
  i(i(x)) -> x
  m(x,i(x)) -> I()
  m(x,m(i(x),y)) -> y
  i(m(x,y)) -> m(i(y),i(x))
  m(Tr(x,y,z),Tr(u,v,w)) -> Tr(pAC(x,u),pAC(y,v),pAC(z,w))
  m(T(x),T(y)) -> T(pAC(x,y))
  m(M(),M()) -> I()
  m(T(z),Tr(x,0(),0())) -> m(Tr(x,0(),0()),T(z))
  m(T(z),M()) -> m(M(),T(minus(z)))
  m(Tr(x,y,z),M()) -> m(M(),Tr(minus(x),minus(y),z))

Proof:
 Open