COMMENT ā VALID 00002 PAGES C REC PAGE DESCRIPTION C00001 00001 C00002 00002 \input jmclet C00003 ENDMK Cā; \input jmclet \jmclet \address Dr. John Fox, Editor The Knowledge Engineering Review P. O. Box 123 Lincoln's Inn Fields London WC2A 3PX England \body Dear Dr. Fox: Enclosed is a commentary on the Lam article. I hope it is not too late. \closing Sincerely, John McCarthy \endletter \end