In an engine structured to introduce fresh air and an EGR gas into a cylinder, the EGR gas is introduced into the cylinder at least at a part of a compression stroke using {TAIL ~ a pressure} in {HEAD ~ a combustion chamber} at least at a part of a power stroke 
In an engine structured to introduce fresh air and an EGR gas into a cylinder , the EGR gas is introduced into the cylinder at least at a part of a compression stroke using { TAIL ~ a pressure } in { HEAD ~ a combustion chamber } at least at a part of a power stroke
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