(<=> (Division-Ring ?Domain ?Plus-Op ?Zero-Id ?Mult-Op ?One-Id) (And (Ring ?Domain ?Plus-Op ?Zero-Id ?Mult-Op ?One-Id) (Group (Kappa (?X) (And (Instance-Of ?X ?Domain) (/= ?X ?Zero-Id))) ?Mult-Op ?One-Id)))
(<=> (Division-Ring ?Domain ?Plus-Op ?Zero-Id ?Mult-Op ?One-Id) (And (Ring ?Domain ?Plus-Op ?Zero-Id ?Mult-Op ?One-Id) (Group (Kappa (?X) (And (Instance-Of ?X ?Domain) (/= ?X ?Zero-Id))) ?Mult-Op ?One-Id))) (Subrelation-Of Field Division-Ring) (<=> (Field ?Domain ?Plus-Op ?Zero-Id ?Mult-Op ?One-Id) (And (Division-Ring ?Domain ?Plus-Op ?Zero-Id ?Mult-Op ?One-Id) (Commutative ?Plus-Op ?Domain)))