/* U_A.G: procedure to return (deterministic,publicly observable) component of
          player a's utility function. Private information part is an additive
	  extreme value distributed shock known to prisoner a but not to 
	  prisoner b.

	  Inputs: 

	  d_a: decision of prisoner a, 1 = confess, 0= don't confess
	  d_b: decision of prisoner b, 1 = confess, 0= don't confess
	  x_a: prisoner a's observable type, assumed to be restricted to [0,1]

	  John Rust, University of Maryland, November, 2005 */

   proc (1)=u_a(d_a,d_b,x_a);


       if ((d_a == 1)*(d_b==1));

            retp (cc_a*x_a);

       elseif ((d_a==0)*(d_b==0));

            retp (dd_a*x_a);

       elseif ((d_a==1)*(d_b==0));

            retp (cd_a*x_a);

       else;

            retp (dc_a*x_a);

       endif;

   endp;