You need to answer the question 'Are the given steps in order?', given a set of steps describing a process. Your answer must be either Yes or No. If the answer is No, that means the steps are out of order and do not make sense in the order they are in. If the answer is Yes, that means the steps are in order and make sense in the order that they are in. A set of steps are not in order if the steps reference information that is introduced in a later step

Example Input:  ['One type of air pollution is the addition of carbon dioxide gas into the air', 'Some scientists believe that releasing too much carbon dioxide into the atmosphere is one of the causes of global warming', 'This upsets the balance of the carbon cycle', 'The ozone layer helps protect us from harmful rays from the sun', 'It is getting damaged from air pollution such as methane gas from livestock and CFCs from spray cans', 'Acid rain is created when gasses such as sulfur dioxide get high into the atmosphere', 'The wind can blow these gasses for miles and then they get washed out of the air when it rains', 'This rain is called acid rain and can damage forests and kill fish.'] 
Example Output:   Yes  

Example Input:  ['Solution caves are formed in limestone and similar rocks by the action of water', 'A weak carbonic acid solution is formed', 'Some of the water reaches a zone where all the cracks and pores in the rock are already filled with water', 'After a rain, water seeps into cracks and pores of soil and rock', 'The water percolates beneath the land surface', 'The water combines chemically with the carbon dioxide', 'Rainwater absorbs some carbon dioxide as it passes through the atmosphere and even more as it drains through soil and decaying vegetation', 'This acid slowly dissolves calcite, forms solution cavities, and excavates passageways'] 
Example Output:   No  

Example Input:  ['People breathe and expel carbon dioxide', 'Engines produce carbon dioxide', 'Living things produce waste', 'Waste decomposes', 'Decomposition produces methane', 'Water evaporates', 'Water vapor joins the atmosphere', 'Carbon dioxide, water vapor and methane are greenhouse gases'] 
Example Output:
  Yes