MAYBE ignored inputs: (COMMENT Example 4.3 of [ Ayala-Lincon et al. , LSFA 2015 ] ) NRS: [ (0): |- (f []X) -> (f [a][]X) ] Check confluence by parallel closed criterion left-linear uniform BCPs: (0 on 0(out)): { |- < (f [a][]X_1) <= (f []X_1) => (f [a][]X_1) >, |- < (f [a][]X_1) <= (f []X_1) => (f [b][]X_1) > } outBCP: |- < (f [a][]X_1), (f [b][]X_1) > is not closed failed to show all BCPs are parallel closed result: MAYBE time: 1 msec.