VINTE: an implementation of internal calculi for lewis’ logics of counterfactual reasoning. We present VINTE, a theorem prover for conditional logics for counterfactual reasoning introduced by Lewis in the seventies. VINTE implements some internal calculi recently introduced for the basic system 𝕍 and some of its significant extensions with axioms ℕ,𝕋,ℂ,𝕎 and 𝔸. VINTE is inspired by the methodology of lean T A P and it is implemented in Prolog. The paper shows some experimental results, witnessing that the performances of VINTE are promising.