SA transactions with related parties; the provision of article 23a of Law 2190/1920 prohibits the provision of a guarantee by the anonymous company in favor of the persons referred to in said provision and not vice versa, i.e. the provision of a guarantee by these persons in favor of the anonymous company, while the underlying relationship of the latter with the anonymous company and its validity or not is irrelevant to the contract of guarantee and to the relationship between lender and guarantor.