MAYBE MAYBE TRS: { if(x, x, if(x, false(), true())) -> true(), if(false(), x, y) -> y, if(true(), x, y) -> x, not(x) -> if(x, false(), true()), and(x, y) -> if(x, y, false()), or(x, y) -> if(x, true(), y), implies(x, y) -> if(x, y, true()), =(x, x) -> true(), =(x, y) -> if(x, y, if(y, false(), true())), =(x, y) -> if(x, y, not(y)) } DUP: We consider a duplicating system. Trs: { if(x, x, if(x, false(), true())) -> true(), if(false(), x, y) -> y, if(true(), x, y) -> x, not(x) -> if(x, false(), true()), and(x, y) -> if(x, y, false()), or(x, y) -> if(x, true(), y), implies(x, y) -> if(x, y, true()), =(x, x) -> true(), =(x, y) -> if(x, y, if(y, false(), true())), =(x, y) -> if(x, y, not(y)) } Fail