1.6.0

• allow Coq 8.16
• added a theory of non-symmetric separating relations
• refactored the theory of sub-PCMs and local relations
• added a theory of map prefixes for unionmaps
• added boolean reflection and rcons/last lemmas to prelude, \In lemmas to pred
• refactored automated lemma infrastructure
• extracted sequence intervals into a separate sub-theory
• added several natmap theories required by current FCSL examples (will be deprecated and removed in future releases): continuous & complete maps, leq surgery, exec & growth