22 lines
455 B
Text
22 lines
455 B
Text
inductive Expr
|
|
| Var : UInt32 → Expr
|
|
| Val : UInt32 → Expr
|
|
| Add : Expr → Expr → Expr
|
|
|
|
open Expr
|
|
|
|
def dec (n : UInt32) : UInt32 :=
|
|
if n = 0 then 0 else n-1
|
|
|
|
def mkExpr : UInt32 → UInt32 → Expr | n, v =>
|
|
if n = 0 then Val v
|
|
else Add (mkExpr (n-1) (v+1)) (mkExpr (n-1) (dec v))
|
|
|
|
def eval : Expr → UInt32
|
|
| Var x => 0
|
|
| Val v => v
|
|
| Add l r => eval l + eval r
|
|
|
|
def main : IO UInt32 :=
|
|
IO.println (toString $ eval (mkExpr 26 1)) *>
|
|
pure 0
|