FOIL Summary

FOIL extends CN2 to handle first-order formulas.
It does a general-to-specific search search, adding a single new literal to the preconditions at each step.
The Foil-Gain function is used to select the best literal.
It can learn recursive rules.
If data is noisy, the search will continue until some trade-off occurs between rule accuracy, coverage, and complexity.
FOIL stops when the length of the length of the rule is larger than the data.
FOIL also post-prunes each rule it learns, using the same strategy as ID3 (both by Quinlan).