0 QTRS
from(X) → cons(X, from(s(X))) head(cons(X, XS)) → X 2nd(cons(X, XS)) → head(XS) take(0, XS) → nil take(s(N), cons(X, XS)) → cons(X, take(N, XS)) sel(0, cons(X, XS)) → X sel(s(N), cons(X, XS)) → sel(N, XS)