2 | 12. u: (x,y:Alph*//(x R y)) (x,y:Alph*//(x R y)) 13. v: ((x,y:Alph*//(x R y)) (x,y:Alph*//(x R y)))* 14. Dec( p:((x,y:Alph*//(x R y)) (x,y:Alph*//(x R y))).
(p/p1,p2.(g(p1)) = (g(p2))) = false & mem_f((x,y:Alph*//(x R y)) (x,y:Alph*//(x R y));p;v)) Dec( p:((x,y:Alph*//(x R y)) (x,y:Alph*//(x R y))).
(p/p1,p2.(g(p1)) = (g(p2))) = false & mem_f((x,y:Alph*//(x R y)) (x,y:Alph*//(x R y));p;u.v)) |