# Opaque Predicates

**Flag:** `--opaque`

Wraps every function body inside an always-true conditional. The `else` branch contains unreachable dead code. A static analyser or LLM must prove the predicate is always true before it can ignore the dead branch and the predicate is specifically designed to make that proof non-trivial.

## How it works

Each function body is wrapped in:

```python
if (lambda _x: <always_true_expr>)(n):
    <original body>
else:
    <dead junk>
```

Three predicate variants are used at random:

| Predicate                        | Why it's always true                              |
| -------------------------------- | ------------------------------------------------- |
| `(lambda _x: _x \| 1 != 0)(n)`   | OR-ing any integer with 1 gives a non-zero result |
| `(lambda _x: _x * _x >= 0)(n)`   | Any integer squared is non-negative               |
| `(lambda _x: (_x ^ _x) == 0)(n)` | XOR of any value with itself is always zero       |

## Example

**Before:**

```python
def greet(name):
    print("Hello, " + name)
```

**After:**

```python
def greet(name):
    if (lambda _x: _x * _x >= 0)(42):
        print("Hello, " + name)
    else:
        _dead = 7391
        pass
```

## What it defeats

* **Dead-code elimination in static analysis** the analyser must evaluate the predicate to know the else branch is unreachable.
* **LLM deobfuscation** LLMs tend to consider both branches as potentially live, adding semantic noise to their interpretation.
* **Diff-based analysis** the additional branch structure obscures where the real code is.

## Notes

* Functions with a body of only `pass` are skipped.
* Pairs well with `--flatten` (applied first) so the predicate wraps the already-flattened state machine.
* The dead else branch variable is named with a random string (further obscured by `--carbon`).


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://rodolphes-organization.gitbook.io/anubis/features/opaque.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.