open (out) vs unroll

open (out)

unroll

verb
  • To straighten something that has been rolled, twisted or curled. 

  • To emerge, be revealed or become apparent; to unfold. 

  • To replace (a loop in a program) with a repetitive sequence of the individual instructions that the loop would carry out, sometimes used as an optimization. 

How often have the words open (out) and unroll occurred in a corpus of books? (source: Google Ngram Viewer )