YES(?,O(n^2)) Problem: implies(not(x),y) -> or(x,y) implies(not(x),or(y,z)) -> implies(y,or(x,z)) implies(x,or(y,z)) -> or(y,implies(x,z)) Proof: Matrix Interpretation Processor: dimension: 2 interpretation: [1 4] [0] [or](x0, x1) = [0 0]x0 + x1 + [1], [1 4] [1 1] [14] [implies](x0, x1) = [0 0]x0 + [0 1]x1 + [2 ], [1 12] [1] [not](x0) = [0 1 ]x0 + [0] orientation: [1 16] [1 1] [15] [1 4] [0] implies(not(x),y) = [0 0 ]x + [0 1]y + [2 ] >= [0 0]x + y + [1] = or(x,y) [1 16] [1 4] [1 1] [16] [1 4] [1 4] [1 1] [15] implies(not(x),or(y,z)) = [0 0 ]x + [0 0]y + [0 1]z + [3 ] >= [0 0]x + [0 0]y + [0 1]z + [3 ] = implies(y,or(x,z)) [1 4] [1 4] [1 1] [15] [1 4] [1 4] [1 1] [14] implies(x,or(y,z)) = [0 0]x + [0 0]y + [0 1]z + [3 ] >= [0 0]x + [0 0]y + [0 1]z + [3 ] = or(y,implies(x,z)) problem: Qed