Different theorem provers tend to produce proof objects in different formats and this is especially the case for modal logics. where several deductive formalisms (and provers based on them) have been presented. This work falls within the general project of establishing a common specification language in order to certify proofs given in a wide range of deductive formalisms. In particular. https://www.thebrickes.shop/product-category/amphibian-habitats/