Deducing hidden properties
n x,y,a,b Adjacent([x,y],[a,b])
   [a,b] {[x+1,y], [x-1,y],[x,y+1],[x,y-1]}
Properties of squares:
n s,t At(Agent,s,t) Breeze(t) Breezy(s)

Squares are breezy near a pit:
¡ Diagnostic rule - infer cause from effect
s Breezy(s) r Adjacent(r,s) Pit(r)
¡ Causal rule - infer effect from cause
r Pit(r) [s Adjacent(r,s) Breezy(s) ]