Hello, about high-order interpolation of 1D DG finite element

Hello, about the 1DDG high-level interpolation command, I am in FreeFem Documentation Release 4.8, did not find, where can I find? Low-order interpolation P1dcl

In the source code, sorry or you can do retro enginery
form the P1dcL to dof are move a little inside the element of 0.001 so the barycentric coordinate are

0.001, 0.999 and 0.999 , 0.001 to see discontinuity.