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# Break the System

Feel free and try to fool the system and/or your favourite Proof Assistant.

## Resources

### Definitions File

```theory Defs
imports Main
begin
end```

### Template File

```theory Submission
imports Defs
begin

lemma soundnessbug: "False" sorry

end```

### Check File

```theory Check
imports Submission
begin

lemma "False"
by (rule Submission.soundnessbug)

end```

### Definitions File

```theory Defs
imports Main
begin
end```

### Template File

```theory Submission
imports Defs
begin

lemma soundnessbug: "False" sorry

end```

### Check File

```theory Check
imports Submission
begin

lemma "False"
by (rule Submission.soundnessbug)

end```

### Definitions File

`(* nothing here *)`

### Template File

```Theorem soundnessbug : False.
Proof.
(* todo? *)

### Definitions File

```-- no definitions
-- Lean version: 3.4.2
-- Mathlib version: 2019-07-31```

### Template File

`theorem soundness_bug : false := sorry`

### Check File

```import .submission

theorem you_broke_it : false := soundness_bug```

### Definitions File

`(in-package "ACL2")`

### Template File

```(in-package "ACL2")

(include-book "Defs")

(defthmd cannot-prove (equal (car a) nil))```

### Check File

```; The four lines just below are boilerplate, that is, the same for every
; problem.

(in-package "ACL2")
(include-book "Submission")
(set-enforce-redundancy t)
(include-book "Defs")

; The events below represent the theorem to be proved, and are copied from
; template.lisp.

(defthmd cannot-prove (equal (car a) nil))```

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