Section ToTarski.
Context {Σ_funcs : funcs_signature}.
Context {Σ_preds : preds_signature}.
Program Instance interp_kripke {domain} (I : interp domain) : kmodel domain :=
{| nodes := unit ; reachable u v := True |}.
Next Obligation.
- now apply I in X.
Defined.

Lemma kripke_tarski {ff : falsity_flag} domain (I : interp domain) rho phi :
rho ⊨ phi <-> ksat (interp_kripke I) tt rho phi.