tuned aeconv: test plain aconv before expensive eta_contract;
tuned aeconv: test plain aconv before expensive eta_contract;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle