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
/*
* SPDX-License-Identifier: MIT
* Copyright (c) 2023 - 2026. The DeepCausality Authors and Contributors. All Rights Reserved.
*/
//! `Prob(f64)` — a probability in `[0, 1]`: a product `CommutativeMonoid` (the `All` reducer) and
//! an MV-algebra [`Verdict`](crate::Verdict) (`meet = min`, `join = max`, `complement = 1 − p`).
use crate::{CommutativeMonoid, Monoid, Verdict};
/// A probability in `[0, 1]`. The `Monoid` is the product t-norm (identity `1`), giving the
/// `AggregateLogic::All` reducer `∏ pᵢ`; commutative, not idempotent.
#[derive(Debug, Clone, Copy, PartialEq)]
pub struct Prob(pub f64);
impl Monoid for Prob {
#[inline]
fn empty() -> Self {
Prob(1.0)
}
#[inline]
fn combine(self, other: Self) -> Self {
Prob(self.0 * other.0)
}
}
impl CommutativeMonoid for Prob {}
// MV-algebra (not Boolean): complement is `1 − p`, meet/join are the [0,1] bounded lattice.
impl Verdict for Prob {
#[inline]
fn bottom() -> Self {
Prob(0.0)
}
#[inline]
fn top() -> Self {
Prob(1.0)
}
#[inline]
fn meet(self, other: Self) -> Self {
Prob(self.0.min(other.0))
}
#[inline]
fn join(self, other: Self) -> Self {
Prob(self.0.max(other.0))
}
#[inline]
fn complement(self) -> Self {
Prob(1.0 - self.0)
}
}