That execution must be consistent with the <i>sequenced before</i> relation,
defined as the partial order requirements set out by the <a href="/ref/spec">Go language specification</a>
for Go's control flow constructs as well as the <a href="/ref/spec#Order_of_evaluation">order of evaluation for expressions</a>.
</p>

<p>
A Go <i>program execution</i> is modeled as a set of goroutine executions,