Lines 5-6, characters 2-3:
5 | ..let y = if false then (fun z -> 1) else (fun z -> x 4 + 1) in
6 |   y..
Error: This kind of expression is not allowed as right-hand side of "let rec"
Line 2, characters 17-18:
2 | let () = ignore (x 42);;
                     ^
Error: Unbound value "x"