Biodivine/LibBDD

This crate provides a basic implementation of binary decision diagrams (BDDs) — a symbolic data structure for representing boolean functions or other equivalent objects (such as bit-vector sets).

Compared to other popular implementations, every BDD owns its memory. It is thus trivial to serialise, but also to share between threads. This makes it useful for applications that process high number of BDDs concurrently.

We currently provide support for explicit operations as well as evaluation of basic boolean expressions and a custom bdd macro for hybrid usage:

use biodivine_lib_bdd::*;

fn demo() {
    let vars = BddVariableSet::new(vec!["a", "b", "c"]);
    let a = vars.mk_var_by_name("a");
    let b = vars.mk_var_by_name("b");
    let c = vars.mk_var_by_name("c");
    
    let f1 = a.iff(&b.not()).or(&c.xor(&a));
    let f2 = vars.eval_expression_string("(a <=> !b) | c ^ a");
    let f3 = bdd!((a <=> (!b)) | (c ^ a));
    
    assert!(!f1.is_false());
    assert_eq!(f1.cardinality(), 6.0);
    assert_eq!(f1, f2);
    assert_eq!(f2, f3);
    assert!(f1.iff(&f2).is_true());
    assert!(f1.iff(&f3).is_true());
}

Additionally, we provide serialisation into a custom string and binary formats as well as .dot. For a more detailed description, see the tutorial module documentation. There is also an experimental support for converting BDDs back into boolean expressions.