1% DEPTH-BOUNDED META-INTERPRETER
    2% CILog code. Copyright David Poole, 1997.
    3
    4% bprove(G,D) is true if G can be proven with depth no more than D.
    5% This assumes that D is bound when called.
    6
    7bprove(true,D).
    8bprove((A & B),D) <-
    9   bprove(A,D)&
   10   bprove(B,D).
   11bprove(H,D)