YES (VAR x) (RULES not(not(n0())) -> n0() and(x,not(n0())) -> x or(x,not(n0())) -> not(n0()) n1() -> not(n0()) or(x,n0()) -> x and(x,n0()) -> n0() ) (COMMENT Termination is shown by LPO with precedence: or > and > n1 > n0 > not )