Resumen de On functions that cannot be mv-truth values in algebraic structures.
It is shown, in a general frame and playing with idempotency, that in order to have on a given lattice a Multiple Valued Logic preserving the lattice structure, the only t-norms and t-conorms allowing to modelize the truth values of a v b, a ^ b and a --> b are Min and Max, respectively, apart from ordinal sums.
