lean4-htt/tests/pkg/module/Module/NonModule.lean
Joachim Breitner f20cae3729
fix: no defeq equations for irreducible definitions (#12429)
This PR sets the `irreducible` attribute before generating the equations
for recursive definitions. This prevents these equations to be marked as
`defeq`, which could lead to `simp` generation proofs that do not type
check at default transparency.

This issue is surfacing more easily since well-founded recursion on
`Nat` is implemented with a dedicated fix point operator (#7965). Before
that, `WellFounded.fix` was used, which is inherently not reducing, so
we did get the desired result even without the explicit reducibility
setting.

Fixes #12398.
2026-02-11 11:49:10 +00:00

84 lines
2.5 KiB
Text

import Module.Basic
import Lean
/-- info: @[defeq] theorem f.eq_def : f = 1 -/
#guard_msgs in #print sig f.eq_def
/-- info: @[defeq] theorem f.eq_unfold : f = 1 -/
#guard_msgs in #print sig f.eq_unfold
/-- info: @[defeq] theorem f_struct.eq_1 : f_struct 0 = 0 -/
#guard_msgs in #print sig f_struct.eq_1
/--
info: theorem f_struct.eq_def : ∀ (x : Nat),
f_struct x =
match x with
| 0 => 0
| n.succ => f_struct n
-/
#guard_msgs in #print sig f_struct.eq_def
/--
info: theorem f_struct.eq_unfold : f_struct = fun x =>
match x with
| 0 => 0
| n.succ => f_struct n
-/
#guard_msgs in #print sig f_struct.eq_unfold
/-- info: theorem f_wfrec.eq_1 : ∀ (x : Nat), f_wfrec 0 x = x -/
#guard_msgs(pass trace, all) in #print sig f_wfrec.eq_1
/--
info: theorem f_wfrec.eq_def : ∀ (x x_1 : Nat),
f_wfrec x x_1 =
match x, x_1 with
| 0, acc => acc
| n.succ, acc => f_wfrec n (acc + 1)
-/
#guard_msgs(pass trace, all) in #print sig f_wfrec.eq_def
/--
info: theorem f_wfrec.eq_unfold : f_wfrec = fun x x_1 =>
match x, x_1 with
| 0, acc => acc
| n.succ, acc => f_wfrec n (acc + 1)
-/
#guard_msgs(pass trace, all) in #print sig f_wfrec.eq_unfold
/--
info: theorem f_wfrec.induct_unfolding : ∀ (motive : Nat → Nat → Nat → Prop),
(∀ (acc : Nat), motive 0 acc acc) →
(∀ (n acc : Nat), motive n (acc + 1) (f_wfrec n (acc + 1)) → motive n.succ acc (f_wfrec n (acc + 1))) →
∀ (a a_1 : Nat), motive a a_1 (f_wfrec a a_1)
-/
#guard_msgs(pass trace, all) in #print sig f_wfrec.induct_unfolding
/-- info: theorem f_exp_wfrec.eq_1 : ∀ (x : Nat), f_exp_wfrec 0 x = x -/
#guard_msgs(pass trace, all) in
#print sig f_exp_wfrec.eq_1
/--
info: theorem f_exp_wfrec.eq_def : ∀ (x x_1 : Nat),
f_exp_wfrec x x_1 =
match x, x_1 with
| 0, acc => acc
| n.succ, acc => f_exp_wfrec n (acc + 1)
-/
#guard_msgs in #print sig f_exp_wfrec.eq_def
/--
info: theorem f_exp_wfrec.eq_unfold : f_exp_wfrec = fun x x_1 =>
match x, x_1 with
| 0, acc => acc
| n.succ, acc => f_exp_wfrec n (acc + 1)
-/
#guard_msgs(pass trace, all) in #print sig f_exp_wfrec.eq_unfold
/--
info: theorem f_exp_wfrec.induct_unfolding : ∀ (motive : Nat → Nat → Nat → Prop),
(∀ (acc : Nat), motive 0 acc acc) →
(∀ (n acc : Nat), motive n (acc + 1) (f_exp_wfrec n (acc + 1)) → motive n.succ acc (f_exp_wfrec n (acc + 1))) →
∀ (a a_1 : Nat), motive a a_1 (f_exp_wfrec a a_1)
-/
#guard_msgs(pass trace, all) in #print sig f_exp_wfrec.induct_unfolding