YES(?,O(n^2)) TRS: { implies(x, or(y, z)) -> or(y, implies(x, z)), implies(not x, y) -> or(x, y), implies(not x, or(y, z)) -> implies(y, or(x, z)) } DUP: We consider a non-duplicating system. Trs: { implies(x, or(y, z)) -> or(y, implies(x, z)), implies(not x, y) -> or(x, y), implies(not x, or(y, z)) -> implies(y, or(x, z)) } Matrix Interpretation: Interpretation class: triangular [X1] [1 1][X1] [3] [not]([X0]) = [0 0][X0] + [2] [X3] [X1] [1 1][X3] [1 2][X1] [0] [implies]([X2], [X0]) = [0 0][X2] + [0 1][X0] + [3] [X3] [X1] [1 1][X3] [1 0][X1] [0] [or]([X2], [X0]) = [0 0][X2] + [0 1][X0] + [2] Qed