> as lemmas

1970 Proc. Third Internat. Cryogenic Engin. Conf. 25–27 May 1970 13/2 There would seem to be a need to define the distinction between cryocooler and cryorefrigerator... On the whole, a cooler is smaller than a refrigerator, and moreover it usually has no moving parts.

2004 Energy Optimization News (Nexis) Apr. All cryocoolers lose efficiency as they approach absolute zero.