let cons_false = List.map mk_con cfl in
let other_cols = List.map (fun (p, _) -> conv p) el in
let cols = if first = "" then other_cols else first :: other_cols in
let cons_false = List.map mk_con cfl in
let other_cols = List.map (fun (p, _) -> conv p) el in
let cols = if first = "" then other_cols else first :: other_cols in