DEFINITION MODULE ZBrentM;

   (* EXPORT QUALIFIED ZBrent; *)

   FROM NRMath IMPORT RealFunction;

   PROCEDURE ZBrent(fx: RealFunction; x1, x2, tol: REAL): REAL; 
   (*
     Using Brent's method, find the root of a function fx known to lie between
     x1 and x2. The root, returned as ZBrent, will be refined until its accuracy
     is tol.
   *)

END ZBrentM.