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))}
 POP* + Boolean Semantic Labelling:
  Normal positions:
  pi(b_sl=1) = [1], pi(b_sl=0) = [1], pi(c_sl=1) = [1], pi(c_sl=0) = [1], pi(d_sl=1) = [1], pi(d_sl=0) = [1]
  
Safe positions:
   pi(a_sl=1) = [1], pi(a_sl=0) = [1], pi(u_sl=1) = [1], pi(u_sl=0) = [1], pi(e_sl=1) = [1], pi(e_sl=0) = [1]
  
Precedence:
   b_sl=0 > e_sl=0, 
   b_sl=0 > a_sl=0, 
   d_sl=0 > e_sl=0, 
   d_sl=0 > u_sl=0, 
   d_sl=0 > c_sl=0, 
   c_sl=0 > b_sl=0
   empty
  
Interpretation:
   e^(1):
   0 | 0
   1 | 1
   u^(1):
   0 | 0
   1 | 0
   d^(1):
   0 | 0
   1 | 0
   c^(1):
   0 | 0
   1 | 0
   b^(1):
   0 | 0
   1 | 0
   v^(1):
   0 | 0
   1 | 1
   a^(1):
   0 | 0
   1 | 0
   
  
Labelling:
   e^(1):
   0 | 0
   1 | 0
   u^(1):
   0 | 0
   1 | 0
   d^(1):
   0 | 0
   1 | 0
   c^(1):
   0 | 0
   1 | 0
   b^(1):
   0 | 0
   1 | 0
   v^(1):
   0 | 0
   1 | 0
   a^(1):
   0 | 0
   1 | 0
   
  
Labelled predicative System:
   {         d_sl=0(x;) -> e_sl=0(;u_sl=0(;x)),
             d_sl=0(x;) -> e_sl=0(;u_sl=0(;x)),
    d_sl=0(u_sl=0(;x);) -> c_sl=0(x;),
    d_sl=0(u_sl=0(;x);) -> c_sl=0(x;),
    c_sl=0(u_sl=0(;x);) -> b_sl=0(x;),
    c_sl=0(u_sl=0(;x);) -> b_sl=0(x;),
    v_sl=0(e_sl=0(;x);) -> x,
    v_sl=0(e_sl=0(;x);) -> x,
    b_sl=0(u_sl=0(;x);) -> a_sl=0(;e_sl=0(;x)),
    b_sl=0(u_sl=0(;x);) -> a_sl=0(;e_sl=0(;x))}
  

  Qed