%------------------------------------------------------------------------------
% Fields definition file
%
%     Author: Rick Butler
%             David Lester, Manchester University & NIA
%
%     Version 1.0            3/1/02
%     Version 1.1           12/3/03   New library structure
%     Version 1.2            5/5/04   Reworked for definition files DRL
%------------------------------------------------------------------------------

field_def[T:Type+,+,*:[T,T->T],zero,one:T]: THEORY

BEGIN

   IMPORTING division_ring_def[T,+,*,zero,one]

   field?(S:set[T]): bool = division_ring?(S) AND commutative?[(S)](*)

END field_def