Beginning of section 5.
--- a/Paper/Paper.thy Tue Mar 30 15:07:42 2010 +0200
+++ b/Paper/Paper.thy Tue Mar 30 15:09:26 2010 +0200
@@ -854,7 +854,7 @@
of term-calculi.
*}
-section {* Alpha-Equivalence and Free Variables *}
+section {* Alpha-Equivalence and Free Variables\label{sec:alpha} *}
text {*
Our choice of syntax for specifications of term-calculi is influenced by the existing
@@ -1269,7 +1269,40 @@
*}
-section {* The Lifting of Definitions and Properties *}
+section {* The Lifting of Definitions and Properties *}
+
+text {*
+ To define quotient types of the raw types we first show that the defined relation
+ in an equivalence relation.
+
+ \begin{lemma} The relations $\approx_1,\ldots,\approx_n,\approx_{bn1},\ldots,\approx_{bnm}$
+ defined as above are equivalence relations.
+ \end{lemma}
+ \begin{proof}
+ Reflexivity by induction on the raw datatype, symmetry and transitivity by
+ induction on the alpha equivalence relation. Using lemma \ref{alphaeq}, the
+ conditions follow by simple calculations.
+ \end{proof}
+
+ \noindent We then define the quotient types @{text "ty\<^isub>1\<^isup>\<alpha> \<dots> ty\<^isub>n\<^isup>\<alpha>"}. To lift the raw
+ definitions to the quotient type, we need to prove that they \emph{respect} the
+ relation. We follow the definition of respectfullness given by
+ Homeier~\cite{Homeier05}. The intuition behind a respectfullness condition is that
+ when a function (or constructor) is given arguments that are alpha-equivalent the
+ results are also alpha equivalent. For arguments that are not of any of the relations
+ taken into account, equvalence is replaced by equality.
+
+% Could be written as a \{lemma}
+ In particular the respectfullness condition for a @{text "bn"} function means that for
+ alpha equivalent raw terms it returns the same bound names. Thanks to the
+ restrictions on the binding functions introduced in Section~\ref{sec:alpha}, we can
+ show that are respectful. With this we can show the respectfullness of @{text "fv_ty"}
+ functions by induction. Respectfullness of permutations is a direct consequence
+ of equivariance. Respectfullness of type constructors and of @{text "alpha_bn"} follows
+ by induction from type definitions.
+
+
+*}
text {*
Restrictions