> For the complete documentation index, see [llms.txt](https://slm-lab.gitbook.io/foundations-of-deep-rl/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://slm-lab.gitbook.io/foundations-of-deep-rl/book-errata/chapter-6-advantage-actor-critic.md).

# Chapter 6 Advantage Actor-Critic

### Page 142, Section 6.3 A2C Algorithm, **Algorithm 6.1** 

*Thanks to Jérémie Clair Coté for this correction.*

Algorithm 6.1 A2C, lines 18 and 20:

$$
\theta\_C = \theta\_C + \alpha\_C \nabla\_{\theta\_C} L\_{val}(\theta\_C)
$$

$$
\theta\_A = \theta\_A + \alpha\_A \nabla\_{\theta\_A} L\_{pol}(\theta\_A)
$$

each contain a typo. The second term on the right hand side of each equation should be subtracted not added since the loss is being minimized. They should read:

$$
\theta\_C = \theta\_C - \alpha\_C \nabla\_{\theta\_C} L\_{val}(\theta\_C)
$$

$$
\theta\_A = \theta\_A - \alpha\_A \nabla\_{\theta\_A} L\_{pol}(\theta\_A)
$$