% Ternary boolean algebra:  g(g(x) = x.

set(auto).

list(usable).
x = x.
f(f(v,w,x),y,f(v,w,z)) = f(v,w,f(x,y,z)).

f(y,x,x) = x.
f(x,x,y) = x.
f(g(y),y,x) = x.
f(x,y,g(y)) = x.
g(g(a)) != a.
end_of_list.