prefer global Quotient_Info lookup to accomodate Quotient_Term, which is not quite localized yet (cf. 9fd6fce8a230);
Arith = FOL +
classes arith < term
consts "0" :: "'a::arith" ("0")
"1" :: "'a::arith" ("1")
"+" :: "['a::arith,'a] => 'a" (infixl 60)
end