/*

set(ground_body,true).
s([a],P).
Variables: [(1,[]),(2,[]),(3,[])]
P = 0.1719 ? ;

set(ground_body,false).
   ?- s([a],P).
P = 0.099 ?
*/

a:0.1:-p(X).

p(1):0.9.

p(2):0.9.