Some more excerpts of textbooks from our data set that describe (a) complementary angles, (b) exterior angles, and (c) parallelogram diagonal bisection axioms. Each excerpt contains rich typographical features that can be used to harvest the axioms. (a) For the complementary angles mention, the textbook explicitly labels the section name “5.2.1 Complementary Angles” with boldface and color; the axiom name “complementary angles” is in bold font, and there is a supporting figure. (b) For the exterior angles mention, the axiom statement is boldfaced, the axiom rule is mentioned via an equation (which is emphasized with the boldfaced string “To show”), and there is a supporting figure. (c) For the parallelogram diagonal bisection mention, the axiom statement is emphasized with the boldfaced string “Property,” the axiom statement itself is italicized, there is a supporting figure, and the axiom rule is written as an equation. Our model will leverage such rich contextual and typographical information (when available) to accurately harvest axioms and then parses them to horn-clause rules.