A computer tutor for logic semantics

The authors report on a computer tutor for the semantics of the Prolog subset of predicate calculus. It gives students statements in English to represent in a single line of Prolog, parses their answers, and compares the parses to the parses of correct answers. The tutor focuses on the correct choice of predicates, variables and link between expressions. Students seem to learn predicate calculus better using the tutor than with paper and pencil exercises.