RBFS
RBFS (node : N, value: F(N), bound : B)
IF f(N)>B, RETURN f(N)
IF N is a goal, EXIT algorithm
IF N has no children, RETURN infinity
FOR each child Ni of N
IF f(N)<F(N) THEN F[i] := MAX(F(N),f(Ni))
ELSE F[i] := f(Ni)
sort  Ni and F[i] in increasing order of F[i]
IF only one child, F[2] := infinity
WHILE (F[1] <= B and F[1] < infinity)
F[1] := RBFS(N1, F[1], MIN(B, F[2]))
Insert N1 and F[1] in sorted order
RETURN F[1]