1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
open Core
type lean_expression =
| Comment of string
| Identifier of string
| Bool of bool
| String of string
| Number of float
| List of lean_expression list
| Tuple of lean_expression list
| Application of lean_expression * lean_expression list
| Define of string * lean_expression
| Inductive of string * judgement list * (string * lean_expression list * lean_expression list) list
| ForAll of judgement * lean_expression
| Exists of judgement * lean_expression
and judgement = string list * string
let fmt_judgement : judgement -> string = function
| vars, t -> Printf.sprintf "(%s : %s)" (String.concat ~sep:" " vars) t
let rec fmt_lean_expression : lean_expression -> string = function
| Comment s -> Printf.sprintf "\n-- %s\n" s
| Identifier s -> s
| Bool b -> if b then "True" else "False"
| String s -> Printf.sprintf "\"%s\"" s
| Number n -> Float.to_string n
| List xs ->
Printf.sprintf "[%s]"
(String.concat ~sep:", " (List.map ~f:fmt_lean_expression xs))
| Tuple xs ->
Printf.sprintf "(%s)"
(String.concat ~sep:", " (List.map ~f:fmt_lean_expression xs))
| Application (head, args) ->
Printf.sprintf "(%s %s)" (fmt_lean_expression head)
(String.concat ~sep:" " (List.map ~f:fmt_lean_expression args))
| Define (ident, expr) ->
Printf.sprintf "def %s := (%s)" ident (fmt_lean_expression expr)
| ForAll (j, expr) ->
Printf.sprintf "∀ %s, %s" (fmt_judgement j) (fmt_lean_expression expr)
| Exists (j, expr) ->
Printf.sprintf "∃ %s, %s" (fmt_judgement j) (fmt_lean_expression expr)
| Inductive (name, judgements, arms) ->
let fmt_arm (arm_name, exprs, values) =
let head =
Printf.sprintf
"%s %s"
name
(List.map ~f:fmt_lean_expression values |> String.concat ~sep:" ")
in
let body =
List.map ~f:fmt_lean_expression exprs
|> String.concat ~sep:" → "
in
Printf.sprintf " | %s : %s → %s" arm_name body head
in
Printf.sprintf "inductive %s %s where\n%s" name
(List.map ~f:fmt_judgement judgements |> String.concat ~sep:" ")
(List.map ~f:fmt_arm arms |> String.concat ~sep:"\n")
|
