The clause compromise not can consider nor a a pact of the contract preliminary of sale nor one element such contract: is, instead, a contracttt o autonomous ad effects procedural, that can ma should not be content in a document with the contract preliminary. between i two contracts, date la lor o autonomous function, not exists a ratio of accessory, as, moreover, expressly foreseen by art. 808, co. 2, cod. proc. civ., in base which L L A validity (and, therefore, even the efficacy) of the clause skuser must be assessed in self -independent way compared to the contract per which it it refers.