(px0 : a00 = a10) (px1 : a01 = a11) (p0x : a00 = a01) : {p1x : a10 = a11 & PathSquare px0 px1 p0x p1x}. Proof. exists (px0^ @ p0x @ px1). by destruct px0, px1, p0x. Defined.
Require Import Basics. Require Import Types.Paths Types.Prod. Require Import DPath. Section PathSquaresFromPaths. End PathSquaresFromPaths.