CeTA: 1: error when switching from the TRS
hd(cons) -> X
tl(cons) -> Y
nats -> adx(zeros)
zeros -> cons
incr(cons) -> cons
adx(cons) -> incr(cons)

to the initial DP problem
dependency pairs: 
nats# -> zeros#
nats# -> adx#(zeros)
adx#(cons) -> incr#(cons)

rewrite system:
hd(cons) -> X
tl(cons) -> Y
nats -> adx(zeros)
zeros -> cons
incr(cons) -> cons
adx(cons) -> incr(cons)

the DP-transformation is not applied correctly.
the TRS is not well-formed
the variable X occurs only in the right-hand side of rule hd(cons) -> X