| C.Prod (n,s,t) -> C.Prod (n, aux s, aux t)
| C.Lambda (n,s,t) -> C.Lambda (n, aux s, aux t)
| C.LetIn (n,s,t) -> C.LetIn (n, aux s, aux t)
| C.Prod (n,s,t) -> C.Prod (n, aux s, aux t)
| C.Lambda (n,s,t) -> C.Lambda (n, aux s, aux t)
| C.LetIn (n,s,t) -> C.LetIn (n, aux s, aux t)