Changes to Cooperative Threading between r2 and r5

'''Cooperative Threading'''

This [threading] model is sometimes called "[fibers]". It is the threading model where each thread must ''explicitly'' give up control of the process or CPU to allow other threads to run. --> This [threading model] is sometimes called "[fibers]". It is the [threading model] where each thread must ''explicitly'' give up control of the process or CPU to allow other [threads] to run.
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Compare to [Preemptive Threading]

Legend

     Only in r2
     Only in r5
     -->      Modified slightly between r2 and r5