(\z z)
-yet when applied to any argument M, all of these will always return M. So they
+yet when applied to any argument `M`, all of these will always return `M`. So they
have the same extension. It's also true, though you may not yet be in a
position to see, that no other function can differentiate between them when
they're supplied as an argument to it. However, these expressions are all
let x match 2
in (x, x)
-evaluates to the ordered pair (2, 2). It may be helpful to think of
+evaluates to the ordered pair `(2, 2)`. It may be helpful to think of
a redex in the lambda calculus as a particular sort of `let`
construction.