YES (VAR x2 x0 x1 a b) (RULES double_divide(double_divide(x2,x0),x1) -> double_divide(inverse(x0),double_divide(inverse(x1),x2)) double_divide(inverse(x0),double_divide(x1,double_divide(x0,x2))) -> double_divide(x2,inverse(x1)) double_divide(x0,double_divide(x1,double_divide(inverse(x0),x2))) -> double_divide(x2,inverse(x1)) inverse(double_divide(x0,x1)) -> double_divide(inverse(x1),inverse(x0)) double_divide(inverse(x0),x0) -> identity() double_divide(identity(),x1) -> inverse(x1) double_divide(x0,double_divide(x1,x0)) -> x1 inverse(inverse(x0)) -> x0 inverse(identity()) -> identity() double_divide(a,inverse(a)) -> identity() multiply(a,b) -> double_divide(inverse(a),inverse(b)) double_divide(a,identity()) -> inverse(a) ) (COMMENT Termination is shown by EKBO with interpretations on natural numbers double_divide_A(x1,x2) = x1 + x2 + 1 identity_A = 1 multiply_A(x1,x2) = x1 + x2 + 1 inverse_A(x1) = x1 double_divide#_A(x1,x2) = 0 identity#_A = 0 weights w0 = 2 w(double_divide) = 0 w(identity) = 3 w(multiply) = 1 w(inverse) = 0 and precedence: inverse > double_divide > multiply > identity )