  This paper treats nonrelativistic matter and a scalar field $\phi$ with a
monotonically decreasing potential minimally coupled to gravity in flat
Friedmann-Lema\^{i}tre-Robertson-Walker cosmology. The field equations are
reformulated as a three-dimensional dynamical system on an extended compact
state space, complemented with cosmographic diagrams. A dynamical systems
analysis provides global dynamical results describing possible asymptotic
behavior. It is shown that one should impose \emph{global and asymptotic}
bounds on $\lambda=-V^{-1}\,dV/d\phi$ to obtain viable cosmological models that
continuously deform $\Lambda$CDM cosmology. In particular we introduce a
regularized inverse power-law potential as a simple specific example.
