Forward positively regressive
From timescalewiki
Let $\mathbb{T}$ be a time scale. Let $p \colon \mathbb{T} \rightarrow \mathbb{C}$. We say that $p$ is (forward) positively regressive if for all $t \in \mathbb{T}^{\kappa}$ $$1+\mu(t)p(t) > 0.$$