Source — Euclid's Elements, encoded as an rrxiv paper

X.14 Proposition X.14

If four straight lines be proportional, and the square on the first be greater than the square on the second by the square on a straight line commensurable with the first, the square on the third will also be greater than the square on the fourth by the square on a straight line commensurable with the third.

lines 74–74 in main.tex