Distinguishing every finitely generated field of characteristic \neq2 by a single field axiom

We show that the isomorphy type of every finitely generated field $K$ with $\text{chr}(K)\mathrm{\ne }2$ is encoded by a $\mathit{\text{single}}\mathit{\text{ha}}\mathit{\text{3explicit}}\mathit{\text{ha}}\mathit{\text{3axiom}}$ $\text{istp}K\text{\hspace{0.17em}⁣}$ $\mathit{\text{in}}\mathit{\text{ha}}\mathit{\text{3the}}\mathit{\text{ha}}\mathit{\text{3language}}\mathit{\text{ha}}\mathit{\text{3of}}\mathit{\text{ha}}\mathit{\text{3fields}}$, i.e., for all finitely generated fields $L$ one has: $\text{istp}K$ holds in $L$ if and only if $K\cong L$ as fields. This extends earlier results by \nmnm{\footnotesize\sc Julia Robinson, Rumely, Poonen, Scanlon}, the author, and others.