Negative lambda in Wachter method?

[tombewley]

If I understand correctly, this line periodically (every n_iter iterations) reduces lambda by $0.05$:

CARLA/carla/recourse_methods/catalog/wachter/library/wachter.py

Line 146 in 24db00a

lamb -= 0.05

However, the default value of lambda is $0.01$:

CARLA/carla/recourse_methods/catalog/wachter/model.py

Line 63 in 24db00a

"lambda_": 0.01,

Does this mean that (with the default settings) lambda becomes negative as soon as the first subtraction is made? Correct me if I'm wrong, but my understanding is that lambda should always be positive (otherwise the loss function incentivises moving further from the factual instance).