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))}
 LMPO:
  Quasi-Precedence:
  d ~ c ~ b
  
Normal:
   pi(b) = [1], pi(c) = [1], pi(d) = [1]
  
Safe:
   
  
Predicative System:
   {    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;);)}
  

   
  

  Qed