MAYBE
Input TRS:
    1: a() -> a() | b() --> x | c() --> x
    2: b() -> d() | d() --> x | e() --> x
    3: c() -> d() | d() --> x | e() --> x
Infeasibility test:
    b() --> x
    c() --> x
Co-Order(NegReal,≥,Sum) ...Co-QLPOpS ...Co-QWPOpS(PosReal,>,Sum) ...Co-Order(PosReal,≥,Sum-Sum; PosReal,≥,Sum-Sum) ...failed.