From P ≠ NP to monotone circuits of super-polynomial size. Abstract: We report on our work to develop an Isabelle-formalization of a proof by Lev Gordeev. That proof aims at showing that the NP-complete problem CLIQUE is not contained in P, since any Boolean circuit that solves CLIQUE will have super-polynomial size. Initially, minor flaws have been identified and could quickly be repaired by mild adjustments of definitions and statements. However, there also have been more serious problems, where then we multiple times contacted Gordeev, who proposed more severe changes in the definitions and statements. In every iteration, Isabelle quickly pointed us to those proof steps that then needed to be adjusted, without having to perform a tedious manual rechecking of all proofs. Although the overall proof is still in a broken state, the problems are restricted to those parts that handle negations in circuits. Consequently the super-polynomial lower bound is valid for monotone circuits: if any such circuit solves CLIQUE for graphs with m vertices, then the size of the circuit is at least (m^(1/7))^(m^(1/8)) for sufficiently large m.