--- a/Paper/Paper.thy Wed Jul 14 21:30:52 2010 +0100
+++ b/Paper/Paper.thy Thu Jul 15 09:40:05 2010 +0100
@@ -1354,8 +1354,8 @@
Recall that @{text ANil} and @{text "ACons"} have no
binding clause in the specification. The corresponding free-atom
function @{text "fa\<^bsub>assn\<^esub>"} therefore returns all free atoms
- occurring in an assignment (in case of @{text "ACons"}, they are given by
- calls to @{text supp}, @{text "fa\<^bsub>trm\<^esub>"} and @{text "fa\<^bsub>assn\<^esub>"}).
+ occurring in an assignment (in case of @{text "ACons"}, they are given in
+ terms of @{text supp}, @{text "fa\<^bsub>trm\<^esub>"} and @{text "fa\<^bsub>assn\<^esub>"}).
The binding only takes place in @{text Let} and
@{text "Let_rec"}. In case of @{text "Let"}, the binding clause specifies
that all atoms given by @{text "set (bn as)"} have to be bound in @{text
@@ -1592,7 +1592,7 @@
in the clause for @{text "Let"} (which is has
a non-recursive binder). The underlying reason is that the terms inside an assignment are not meant
to be ``under'' the binder. Such a premise is \emph{not} needed in @{text "Let_rec"},
- because there everything from the assignment is under the binder.
+ because there all components of an assignment are ``under'' the binder.
*}
section {* Establishing the Reasoning Infrastructure *}
@@ -2064,8 +2064,8 @@
To our knowledge the earliest usage of general binders in a theorem prover
is described in \cite{NaraschewskiNipkow99} about a formalisation of the
algorithm W. This formalisation implements binding in type schemes using a
- de-Bruijn indices representation. Since type schemes of W contain only a single
- binder, different indices do not refer to different binders (as in the usual
+ de-Bruijn indices representation. Since type schemes in W contain only a single
+ place where variables are bound, different indices do not refer to different binders (as in the usual
de-Bruijn representation), but to different bound variables. A similar idea
has been recently explored for general binders in the locally nameless
approach to binding \cite{chargueraud09}. There, de-Bruijn indices consist
@@ -2093,7 +2093,8 @@
representations have to resort to the iterated-single-binders-approach with
all the unwanted consequences when reasoning about the resulting terms.
- Two formalisations involving general binders have also been performed in older
+ In a similar fashion, two formalisations involving general binders have been
+ performed in older
versions of Nominal Isabelle (one about Psi-calculi and one about algorithm W
\cite{BengtsonParow09, UrbanNipkow09}). Both
use the approach based on iterated single binders. Our experience with