two balls

// Two balls in the bag:
// (1) fifty/fifty red (true) or green (false)
// (2) 100% red
//
// Process:
// - pull out the first ball and observe it is red
// - Question: what is the probability the remaining ball is red too?

var model = function() {
  var b1 = flip(0.5)
  var b2 = flip(1)
  var pick = flip(0.5)
  if (pick == true) {
    condition(b1 == true)
    return b2
  } else {
    condition(b2 == true)
    return b1
  }
}
var dist = Infer(model)
viz(dist)