Applying Logical Knowledge

  Path

Recursion, in any language is specified in two steps:

• The boundary condition, or simple degenerate case
• The recursive condition.

In Prolog these often become two rules. Ex, finding the various connections from an East coast city.

• Boundary - there is a flight from here to there.
• Recursive - there is a flight from here to somewhere in between, and it connects to there

connect(FROM, TO) :-
   flight_ew(FROM, TO).
connect(FROM, TO) :-
   flight_ew(FROM, X),
   connect(X, TO).

Copyright ©2005 Amzi! inc.