The metric-locating-dominating bound for doubly resolving sets

Let $G$ be a graph. Write ${\rm \dim}(G)$ for its metric dimension, $\gamma(G)$ for its domination number, and $\psi(G)$ for its doubly resolving number. Metric-locating-dominating bound. For every graph $G$, it holds that

$$\psi(G)\leq {\rm \dim}(G)+\gamma(G).$$

This conjecture is supported by the inequality $\gamma_M(G)\leq {\rm \dim}(G)+\gamma(G)$, where $\gamma_M(G)$ denotes the metric-locating-dominating number. The preceding results establish related bounds, including $\psi(G)\leq 2\gamma_M(G)$, but the stated inequality is not resolved here.