mathlib/test/instance_cache.lean at master · lacker/mathlib · GitHub

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
60
61
62
63
64
65
66
67
68
69
70
71
import tactic.cache

meta def assert_frozen_instances : tactic unit := do
frozen ← tactic.frozen_local_instances,
when frozen.is_none $ tactic.fail "instances are not frozen"

example (α) (a : α) :=
begin
  haveI h : inhabited α := ⟨a⟩,
  assert_frozen_instances,
  exact default α
end

example (α) (a : α) :=
begin
  haveI h := inhabited.mk a,
  assert_frozen_instances,
  exact default α
end

example (α) (a : α) :=
begin
  letI h : inhabited α := ⟨a⟩,
  assert_frozen_instances,
  exact default α
end

example (α) (a : α) :=
begin
  letI h : inhabited α,
  all_goals { assert_frozen_instances },
  exact ⟨a⟩,
  exact default α
end

example (α) (a : α) :=
begin
  letI h := inhabited.mk a,
  exact default α
end

example (α) : inhabited α → α :=
by intro a; exactI default α

example (α) : inhabited α → α :=
begin
  introsI a,
  assert_frozen_instances,
  exact default α
end

example (α β) (h : α = β) [inhabited α] : β :=
begin
  substI h,
  assert_frozen_instances,
  exact default _
end

example (α β) (h : α = β) [inhabited α] : β :=
begin
  unfreezingI { cases _inst_1 },
  assert_frozen_instances,
  subst h, assumption
end

example (α β) (h : α = β) [inhabited α] : β :=
begin
  casesI _inst_1,
  assert_frozen_instances,
  subst h, assumption
end