Environment

ESFM: Prolog Expert System for Forestry Management
A small expert system developed by Steve Jones of Reading University in 1988 for forestry management. The rules are Prolog clauses. Inference is depth-first, backward-chaining, with no explanations of why ESFM asked a question nor how it came to a conclusion.
http://www.cs.cmu.edu/afs/cs/project/ai-repository/ai/areas/expert/systems/esfm/0.html