Exception for (- (log (* (pow lam k) (exp (- k)))) (lgamma (+ k 1)))

Math

\[\log \left({lam}^{k} \cdot e^{-k}\right) - \mathsf{lgamma} \left( k + 1 \right)\]

Reproduce

herbie shell --seed 2020153 
(FPCore (lam k)
  :name "(- (log (* (pow lam k) (exp (- k)))) (lgamma (+ k 1)))"
  :precision binary64
  (- (log (* (pow lam k) (exp (neg k)))) (lgamma (+ k 1.0))))