vie describe a number of special purpose, but domain independent, inference mechanisms.
While these rl1echanisms are limited to certain kinds of inference and
illference rules, they do not rely on special properties of the domain, but on
logical properties of predicates and rules, ~Ihich make them equally applicable to
other domains. These logical properties include: transitivity, functionality and
unarit.y. The union of the~e mechanisms handles nearly all the inference required in
the Mecho project for solving mechanics problems stated in English
