YES (VAR x0 x1 x2 a b) (RULES 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)) double_divide(double_divide(x0,x1),x2) -> double_divide(inverse(x1),double_divide(inverse(x2),x0)) inverse(double_divide(x1,x0)) -> double_divide(inverse(x0),inverse(x1)) double_divide(x0,double_divide(x1,x0)) -> x1 double_divide(identity(),x0) -> inverse(x0) inverse(inverse(x0)) -> x0 double_divide(inverse(x0),x0) -> identity() inverse(identity()) -> identity() double_divide(a,inverse(a)) -> identity() double_divide(a,identity()) -> inverse(a) multiply(a,b) -> double_divide(inverse(a),inverse(b)) ) (COMMENT Termination is shown by EKBO with interpretations on natural numbers double_divide_A(x1,x2) = x1 + x2 + 2 identity_A = 1 multiply_A(x1,x2) = x1 + x2 + 6 inverse_A(x1) = x1 identity#_A = 0 multiply#_A(x1,x2) = x1 + x2 weights w0 = 1 w(double_divide) = 1 w(identity) = 2 w(multiply) = 5 w(inverse) = 0 and precedence: inverse > multiply > double_divide > identity )