An Accumulating Eligibility Trace is a type of eligibility trace where the trace increments in an accumulative way. For the memory vector e_t∈Rb≥0\textbf{e}\_{t} \in \mathbb{R}^{b} \geq \textbf{0}e_t∈Rb≥0:
e_0=0\mathbf{e\_{0}} = \textbf{0}e_0=0
e_t=∇v^(S_t,θ_t)+γλe_t\textbf{e}\_{t} = \nabla{\hat{v}}\left(S\_{t}, \mathbf{\theta}\_{t}\right) + \gamma\lambda\textbf{e}\_{t}e_t=∇v^(S_t,θ_t)+γλe_t