Know what this is below?
1 (Bottom, Longer): H×INT((P+2)÷2)+V×P+L
2 (Second, Shorter): H×INT((P+1)÷2)+V×(P−1)+L
You're right. It's the formula for getting the lace length right for Bi-Colour Lacing.
The most famous Shoelace site in the world is run by Ian Fieggen, a Melbourne bloke. It includes 33 different ways to lace shoes, plus comparisions of lacing methods by comfort, difficulty, visual appeal and ease.
His photos and diagrams are helpful, to the point and a pleasure to view.
Top photo is Black Bam shoes with cyan trim and cyan & black Checkerboard Lacing. Diagram is Lattice lacing.