TRS:
 {   d(x) -> e(u(x)),
  d(u(x)) -> c(x),
  c(u(x)) -> b(x),
  v(e(x)) -> x,
  b(u(x)) -> a(e(x))}
 MPO:
  Prec:
   b > e, 
   b > a, 
   d > e, 
   d > u, 
   d > c, 
   c > b
   empty
  Strict:
   {}
   Weak:
    {}
  Qed