Lemma mem_cohere_step c c' jm jm' Phi (X : rmap) ge : mem_cohere' (m_dry jm) Phi -> sepalg.join (m_phi jm) X Phi -> corestep (juicy_core_sem (cl_core_sem ge)) c jm c' jm' -> exists Phi', sepalg.join (m_phi jm') (age_to (level (m_phi jm')) X) Phi' /\ mem_cohere' (m_dry jm') Phi'.