YES 1 decompositions #0 ----------- 1: not(T()) -> F() 2: not(F()) -> T() 3: not(not(x)) -> x 4: exor(x,T()) -> not(x) 5: exor(x,F()) -> x 6: exor(not(x),y) -> not(exor(x,y)) 7: exor(exor(x,y),z) -> exor(x,exor(y,z)) 8: exor(x,y) -> exor(y,x) @Jouannaud and Kirchner's criterion --- R 1: not(T()) -> F() 2: not(F()) -> T() 3: not(not(x)) -> x 4: exor(x,T()) -> not(x) 5: exor(x,F()) -> x 6: exor(not(x),y) -> not(exor(x,y)) 7: exor(exor(x,y),z) -> exor(x,exor(y,z)) 8: exor(x,y) -> exor(y,x) --- S 1: not(T()) -> F() 2: not(F()) -> T() 3: not(not(x)) -> x 4: exor(x,T()) -> not(x) 5: exor(x,F()) -> x 6: exor(not(x),y) -> not(exor(x,y)) 7: exor(exor(x,y),z) -> exor(x,exor(y,z)) 8: exor(x,y) -> exor(y,x)