moved theorem tags from Drule to PureThy;
replaced kind attribute by kind string;
tuned name_multi: index > 1 only;
added note_thmss_qualified (from Isar/locale.ML);
Arith = FOL +
classes arith < term
consts "0" :: "'a::arith" ("0")
"1" :: "'a::arith" ("1")
"+" :: "['a::arith,'a] => 'a" (infixl 60)
end