list.rb

#convert a list of integers into a list of booleans.
1.9.3p194 :026 > [1,2,3,4].map { |x| x == 3 } => [false, false, true, false] 

# return true if any integer is three
1.9.3p194 :027 > [1,2,3,4].map { |x| x == 3 }.reduce(false,:or) => true 

# return true if ALL integers are three
1.9.3p194 :028 > [1,2,3,4].map { |x| x == 3 }.reduce(true,:and) => false 

# return true if ALL integers are three
1.9.3p194 :031 > [3,3,3,3].map { |x| x == 3 }.reduce(true,:and) => true 

# sum 1 through 20
1.9.3p194 :052 > (1..20).sum => 210 

# sum 1 through 20
1.9.3p194 :055 > (1..20).reduce(0,:+) => 210 

setup.rb

[TrueClass,FalseClass].each do |clazz|                                                                                                                                            
  clazz.class_eval do                                                                                                                                                             
    def or(a)                                                                                                                                                                     
      self or a                                                                                                                                                                   
    end                                                                                                                                                                           
    def and(a)                                                                                                                                                                    
      self and a                                                                                                                                                                  
    end                                                                                                                                                                           
  end                                                                                                                                                                             
end

require 'active_support/all'