# Tag Info

Not sure whether I completely understand the question, but here is my attempt: a naïve reading would allow for Γ, t, or T to contain type variables not mentioned in χ. $\Gamma$, $t$ and $T$ may contain type variables not mentioned in $\mathcal{X}$. The set $\mathcal{X}$ contains only unification variables. That is, fresh variables generated by the typing ...