order of evaluation parse date s - (nf)

[utzoo!decvax!harpo!eagle!mhtsa!alice!alb]

i = 4;
i = i++;

Regardless of whether the increment of the assignment comes first,
i == 5 afterwards.  Think:

If the increment comes first:
i++ (so i == 5)
i = i (so i == 5)

If the assignment comes first:
i = i (so i == 4)
i++ (so i == 5)