require_relative 'number_argument'
require_relative 'apply_to_range'

module ExcelFunctions
  
  def subtract(a,b)
    # return apply_to_range(a,b) { |a,b| subtract(a,b) } if a.is_a?(Array) || b.is_a?(Array)
  
    a = number_argument(a)
    b = number_argument(b)
  
    return a if a.is_a?(Symbol)
    return b if b.is_a?(Symbol)
    
    a - b
  end
  
end
