MAYBE
The TRS could not be proven terminating. The proof attempt took 43505 ms.
Problem 1 remains open; application of the following processors failed [DependencyGraph (56ms), SubtermCriterion (1ms), DependencyGraph (31ms), PolynomialLinearRange4iUR (1264ms), DependencyGraph (27ms), PolynomialLinearRange8NegiUR (6380ms), DependencyGraph (19ms), ReductionPairSAT (35494ms), DependencyGraph (18ms), SizeChangePrinciple (32ms)].
app#(app(filter, f), app(app(cons, x), xs)) | → | app#(filter, f) | app#(app(filter, f), app(app(cons, x), xs)) | → | app#(app(app(consif, app(f, x)), x), app(app(filter, f), xs)) | |
app#(app(filter, f), app(app(cons, x), xs)) | → | app#(app(filter, f), xs) | app#(app(app(consif, true), x), ys) | → | app#(cons, x) | |
app#(app(filter, f), app(app(cons, x), xs)) | → | app#(app(consif, app(f, x)), x) | app#(app(filter, f), app(app(cons, x), xs)) | → | app#(f, x) | |
app#(app(filter, f), app(app(cons, x), xs)) | → | app#(consif, app(f, x)) | app#(app(app(consif, true), x), ys) | → | app#(app(cons, x), ys) |
app(app(app(consif, true), x), ys) | → | app(app(cons, x), ys) | app(app(app(consif, false), x), ys) | → | ys | |
app(app(filter, f), nil) | → | nil | app(app(filter, f), app(app(cons, x), xs)) | → | app(app(app(consif, app(f, x)), x), app(app(filter, f), xs)) |
Termination of terms over the following signature is verified: app, false, true, consif, filter, nil, cons