| Ast.Below (p1, p2) -> let p1 = aux p1 in let p2 = aux p2 in Ast.Below (p1, p2)
| Ast.Above (p1, p2) -> let p1 = aux p1 in let p2 = aux p2 in Ast.Above (p1, p2)
| Ast.Frac (p1, p2) -> let p1 = aux p1 in let p2 = aux p2 in Ast.Frac (p1, p2)
| Ast.Below (p1, p2) -> let p1 = aux p1 in let p2 = aux p2 in Ast.Below (p1, p2)
| Ast.Above (p1, p2) -> let p1 = aux p1 in let p2 = aux p2 in Ast.Above (p1, p2)
| Ast.Frac (p1, p2) -> let p1 = aux p1 in let p2 = aux p2 in Ast.Frac (p1, p2)