wenzelm [Thu, 03 Feb 1994 13:53:44 +0100] rev 251
major cleanup;
added eq_sig;
added print_sg (full contents), pprint_sg (stamps only);
added certify_typ, certify_term;
changed read_typ: result now certified;
wenzelm [Thu, 03 Feb 1994 13:53:08 +0100] rev 250
extend_theory: changed type of "abbrs" arg;
added cterm_fun, read_ctyp (from drule.ML);
ctyp_of, cterm_of, etc.: now use Sign.certify_...;
assumption: now uses Envir.is_empty;
bicompose_aux: fixed BUG (unifier with empty "asol" but non-empty "iTs"
wasn't applied);
fixed axioms_of;
clasohm [Wed, 02 Feb 1994 11:15:22 +0100] rev 249
made error message "file not found" more informative