My Coq compiler is not allowing for inductive propositions as:

```
Inductive relation : nat -> nat -> Prop :=
  | A : relation 1 2
  | B : relation 2 3.
```
Throws: `Error: The reference B was not found in the current environment.`

```
Inductive le : nat -> nat -> Prop :=
  | le_n (n : nat) : le n n
  | le_S (n m : nat) : le n m -> le n (S m).
```
Throws: `Error: The reference m was not found in the current environment.`

My previously running code is not breaking in all the ind. propositions. I don't know if something changed, I'm running these versions:
```
The Coq Proof Assistant, version 8.18.0
compiled with OCaml 5.1.0
```

Any ideas?

If I use only one rule as:
```
Inductive relation : nat -> nat -> Prop :=
  | A : relation 1 2.
```
Works.
So I tried changing from tabs to spaces. I didn't change the Coq version because this is the version that was actually compiling some days ago.