Ordered Reduced Binary Decision Diagrams https://github.com/jwaldmann/haskell-obdd

Latest on Hackage:0.8.1

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

GPL licensed and maintained by Johannes Waldmann

Construct, combine and query OBDDs; an efficient representation for formulas in propositional logic.

This is mostly educational. The BDDs do not share nodes (there is no persistent BDD base) and this might introduce inefficiencies.

An important (for me, in teaching) feature is that I can immediately draw the BDD to an X11 window (via graphviz). For example, to show the effect of different variable orderings, try this in ghci:

import qualified Prelude as P
import OBDD
let f [] = false; f (x:y:zs) = x && y || f zs
display P.$ f P.$ P.map variable [1,2,3,4,5,6]
display P.$ f P.$ P.map variable [1,4,2,5,3,6]

If you want better performance, use CUDD Haskell bindings, see this example.

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