ERF function
    ERF(UpperBound) ERF(UpperBound)
  
  UpperBound
        Number or { Number }
      
      The upper bound.
Returns
        Number or { Number }
      
      The Gauss error function.
Returns the Gauss error function calculated between 0 and an upper bound.
Example
      ERF(0.5)ERF(0,5)
      
    
    Returns roughly 0.52.