NO Problem: b() -> a() b() -> c() c() -> b() c() -> d() Proof: Matrix Interpretation Processor: dimension: 3 interpretation: [0] [d] = [0] [0], [1] [c] = [0] [0], [0] [a] = [0] [0], [1] [b] = [0] [0] orientation: [1] [0] b() = [0] >= [0] = a() [0] [0] [1] [1] b() = [0] >= [0] = c() [0] [0] [1] [1] c() = [0] >= [0] = b() [0] [0] [1] [0] c() = [0] >= [0] = d() [0] [0] problem: b() -> c() c() -> b() Unfolding Processor: loop length: 2 terms: b() c() context: [] substitution: Qed