moved everything related to thms_containing to find_theorems.ML; export is_known; added fact_index_of, valid_thms; gen_read': removed unused dummies option; declare_term(_syntax): canonical argument order; removed declare_terms(_syntax);
moved everything related to thms_containing to find_theorems.ML;
export is_known;
added fact_index_of, valid_thms;
gen_read': removed unused dummies option;
declare_term(_syntax): canonical argument order;
removed declare_terms(_syntax);

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