anchor.diff:          static member singleton scope transformer =
               { Scope = scope; Transformers = FStack.singleton transformer }
   
  +        /// Make from a scope and sequence of transformers.
  +        static member ofSeq scope transformers =
  +            { Scope = scope; Transformers = FStack.ofSeq transformers }
  +
           /// Run the behavior over an array of targets.
           /// OPTIMIZATION: runs transformers in batches for better utilization of instruction cache.
           static member runMany time (constrain : Constraint) (behavior : Behavior<'a, 'b>) (targets : 'a array) =
  
positive.code:                     index <- inc index
                  Output.empty
              let particleBehaviors =
                  let behavior = Behavior.singleton BasicParticle.body (Transformer.force (Velocity Constraint.empty))
                  Behaviors.singleton behavior
              let emitterBehavior = fun _ (emitter : BasicEmitter) ->
                  emitter.Body.Rotation <- emitter.Body.Rotation + 0.05f
                  Output.empty
  
negative.code:         static member singleton behavior =
              { Behaviors = FStack.singleton behavior }
  
          /// Make from a sequence of behaviors.
          static member ofSeq behaviors =
              { Behaviors = FStack.ofSeq behaviors }
  
          /// Add a behavior.
          static member add behavior behaviors =
              { Behaviors = FStack.conj behavior behaviors.Behaviors }
  