bel(system,$B;}$D(B(user,$B9XF~95$((B($B%H%i%Y%i!<%:%A%'%C%/(B))).
bel(system,bel_ref(user,$B6d9T(B_place1,at_loc,$B6d9T(B,[near(at_loc,user)])).
bel(system,know(user,effect($B?=@A(B(user,$B:FH/9T(B($B%H%i%Y%i!<%:%A%'%C%/(B)),$B;}$D(B(user,$B%H%i%Y%i!<%:%A%'%C%/(B)))).
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