+What "sequencing" is and isn't
+------------------------------
+
+We mentioned before the idea that computation is a sequencing of some changes. I said we'd be discussing (fragments of, and in some cases, entire) languages that have no native notion of change.
+
+Neither do they have any useful notion of sequencing. But what this would be takes some care to identify.
+
+First off, the mere concatenation of expressions isn't what we mean by sequencing. Concatenation of expressions is how you build syntactically complex expressions out of simpler ones. The complex expressions often express a computation where a function is applied to one (or more) arguments,
+
+Second, the kind of rebinding we called "shadowing" doesn't involve any changes or sequencing. All the precedence facts about that kind of rebinding are just consequences of the compound syntactic structures in which it occurs.
+
+Third, the kinds of bindings we see in:
+
+ (define foo A)
+ (foo 2)