The evaluation order of some things is undefined (or at least it was), which does leave open possiblities. For example, in
res = f(x) < f(y) < f(z)
the f
calls could be evaluated in parallel if results don’t depend on their order. Guy Steele stated recently that one of the lost features of Fortress he would like to see continued in modern parallel languages is “parallel by default”, where it would require a little effort to make things sequential where needed, rather than requiring a little effort to make things parallel.