MAYBE ignored inputs: (COMMENT a system of beta reduction for the lambda calculus via orthogonal explicit substitution calculus ) NRS: [ (0): |- (app <(lam [a][]X),[]Y>) -> (sub <[a][]X,[]Y>), (1): |- (sub <[a](app <[]X,[]Y>),[]Z>) -> (app <(sub <[a][]X,[]Z>),(sub <[a][]Y,[]Z>)>), (2): |- (sub <[a]a,[]X>) -> []X, (3): |- (sub <[a]b,[]Y>) -> b, (4): b#Y |- (sub <[a](lam [b][]X),[]Y>) -> (lam [b](sub <[a][]X,[]Y>)) ] Check confluence by orthogonality abstract skeleton preserving left-linear check proper overlapping a proper overlap exists 0-1 |- < (sub <[a](sub <[a][]X,[]Y_1>),[]Z_1>) <= (sub <[a](app <(lam [a][]X),[]Y_1>),[]Z_1>) => (app <(sub <[a](lam [a][]X),[]Z_1>),(sub <[a][]Y_1,[]Z_1>)>) > found proper overlaps result: MAYBE time: 4 msec.