MAYBE

Problem:
 a(b(x1)) -> b(r(x1))
 r(a(x1)) -> d(r(x1))
 r(x1) -> d(x1)
 d(a(x1)) -> a(a(d(x1)))
 d(x1) -> a(x1)

Proof:
 DP Processor:
  DPs:
   a#(b(x1)) -> r#(x1)
   r#(a(x1)) -> r#(x1)
   r#(a(x1)) -> d#(r(x1))
   r#(x1) -> d#(x1)
   d#(a(x1)) -> d#(x1)
   d#(a(x1)) -> a#(d(x1))
   d#(a(x1)) -> a#(a(d(x1)))
   d#(x1) -> a#(x1)
  TRS:
   a(b(x1)) -> b(r(x1))
   r(a(x1)) -> d(r(x1))
   r(x1) -> d(x1)
   d(a(x1)) -> a(a(d(x1)))
   d(x1) -> a(x1)
  Open