open Jig;;
let (top, embd, [inf; outf]) =
mix ([[0; 1; 2]; [0; 2; 3]; [0; 3; 4]; [0; 4; 1]],
     [|[|0.; 0.|]; [|2.; 0.|]; [|0.; 1.|];  [|-2.; 0.|]; [|0.; -1.|]|],
     [[1; 4]; [1; 2]]) [|4; 0; 1; 2; 3|] in
let bl = Glue.morphgen (nz (embd, [|1.; -1.; 1.; 1.|])) top [] in
(jig embd bl inf outf).lray ([|1.; -0.5|], [|0.; 1.|])
(* should yield approx ([|1.; 0.5|], [|1.; 0.|]) *);;