The Forster Notebook II

v . m . n . o . are : lunes original: "lune." These refer to the crescent-shaped areas labeled in the accompanying diagram.

the square original: "quadro," represented by the symbol ◻ in the circle original: "abula," likely a contraction or variant for the circular area or the "table" of the diagram. is equal to the lune original: "lunula," represented by the symbol ☽

the b e f n remain from the
circle of a smaller square e f n Leonardo is calculating the remaining area of a circle after a square is inscribed within it.
let the lune be one of those equal
to the remainder of the same
lunes; the lunes are equal original: "co," likely a contraction for "congruent" or "equal."
to the area equal to the f u
square and those circles original: "abu," referring to the circular segments. lunes
to . . . of The text here is fragmentary or abbreviated.