MLN Benchmark

Wolfe

case class World(smokes: Pred[Symbol], cancer: Pred[Symbol], 
                 friends: Pred[(Symbol, Symbol)])
implicit def persons = List('Anna, 'Bob)
def worlds = all(World)

def mln(world: World) = {
  import world._
  sum(persons) { p => 
    1.5 * I(smokes(p) --> cancer(p)) } +
  sum(persons) { p1 => sum(persons) { p2 => 
    1.1 * I(friends(p1, p2) --> (smokes(p1) == smokes(p2))) } }
}

def evidence(world: World) = world.smokes('Anna) && world.friends('Anna, 'Bob)
def query(world: World) = oneHot(world.cancer('Bob))
val mu = expect(worlds where evidence) { mln } { query }
barChart(mu)

Church

(define (implies x y) (or (not x) y))

(define samples
  (mh-query 1000 100
    (define people (list 'anna 'bob))
    (define smokes (mem (lambda (person) (flip))))
    (define cancer (mem (lambda (person) (flip))))
    (define friends (mem (lambda (x y) (flip))))

    (define smokes-cancer (sum (map 
      (lambda (x) (if (implies (smokes x) (cancer x)) 0 -1.5)) 
      people
    )))
    (define friends-smoke (sum (map
        (lambda (x) (sum (map
          (lambda (y) (if (implies (friends x y) (eq? (smokes x) (smokes y))) 0 -1.1))
          people
          )))
        people
    )))    
    (define model (+ smokes-cancer friends-smoke))
    (define evidence (and (smokes 'anna) (friends 'anna 'bob)))

    (cancer 'bob)

    (and evidence (< (uniform 0 1) (exp model)))
  )
)
(hist samples)