Complete TRS - 30.trs

(VAR
	x
)
(RULES
	f(a,a) -> b
	a -> a'
	f(a',x) -> f(x,x)
	f(x,a') -> f(x,x)
	f(a',a') -> b
	b -> f(a',a')
	f(a,a') -> b
	f(a',a) -> b
)