The EPGY Theorem-Proving Environment is designed to help students write ordinary mathematical proofs. The system, used in a selection of computer-based proof-intensive mathematics courses, allowsâ€¦ (More)

In planar networks of soap films, segments meet in triples to form 120â—¦ angles. Such angles are characteristic of nodes in length-minimizing networks. In this paper, we study the geometry ofâ€¦ (More)