treat MinProof like Promise before 725438ceae7c, e.g. relevant for performance of session Corec (due to Thm.derivation_closed/close_derivation);
(*** Isabelle/Pure bootstrap: initial setup ***)
ML_file "General/exn.ML";
ML_file "General/output_primitives.ML";
ML_file "Concurrent/thread_attributes.ML";
ML_file "Concurrent/thread_data.ML";
ML_file "Concurrent/thread_position.ML";
ML_file "ML/ml_recursive.ML";