
diff -r 614c045c5fd4 -r 051a88965e50 doc-src/IsarRef/Thy/document/Generic.tex
--- a/doc-src/IsarRef/Thy/document/Generic.tex	Tue Jun 03 23:46:53 2008 +0200
+++ b/doc-src/IsarRef/Thy/document/Generic.tex	Tue Jun 03 23:47:13 2008 +0200
@@ -230,8 +230,8 @@
   indicate the positions to substitute at.  Positions are ordered from
   the top of the term tree moving down from left to right. For
   example, in \isa{{\isachardoublequote}{\isacharparenleft}a\ {\isacharplus}\ b{\isacharparenright}\ {\isacharplus}\ {\isacharparenleft}c\ {\isacharplus}\ d{\isacharparenright}{\isachardoublequote}} there are three positions
-  where commutativity of \isa{{\isachardoublequote}{\isacharplus}{\isachardoublequote}} is applicable: 1 refers to the
-  whole term, 2 to \isa{{\isachardoublequote}a\ {\isacharplus}\ b{\isachardoublequote}} and 3 to \isa{{\isachardoublequote}c\ {\isacharplus}\ d{\isachardoublequote}}.
+  where commutativity of \isa{{\isachardoublequote}{\isacharplus}{\isachardoublequote}} is applicable: 1 refers to
+  \isa{{\isachardoublequote}a\ {\isacharplus}\ b{\isachardoublequote}}, 2 to the whole term, and 3 to \isa{{\isachardoublequote}c\ {\isacharplus}\ d{\isachardoublequote}}.
 
   If the positions in the list \isa{{\isachardoublequote}{\isacharparenleft}i\ {\isasymdots}\ j{\isacharparenright}{\isachardoublequote}} are non-overlapping
   (e.g.\ \isa{{\isachardoublequote}{\isacharparenleft}{\isadigit{2}}\ {\isadigit{3}}{\isacharparenright}{\isachardoublequote}} in \isa{{\isachardoublequote}{\isacharparenleft}a\ {\isacharplus}\ b{\isacharparenright}\ {\isacharplus}\ {\isacharparenleft}c\ {\isacharplus}\ d{\isacharparenright}{\isachardoublequote}}) you may
@@ -239,9 +239,11 @@
   the behaviour of \isa{subst} is not specified.
 
   \item [\hyperlink{method.subst}{\mbox{\isa{subst}}}~\isa{{\isachardoublequote}{\isacharparenleft}asm{\isacharparenright}\ {\isacharparenleft}i\ {\isasymdots}\ j{\isacharparenright}\ eq{\isachardoublequote}}] performs the
-  substitutions in the assumptions.  Positions \isa{{\isachardoublequote}{\isadigit{1}}\ {\isasymdots}\ i\isactrlsub {\isadigit{1}}{\isachardoublequote}}
-  refer to assumption 1, positions \isa{{\isachardoublequote}i\isactrlsub {\isadigit{1}}\ {\isacharplus}\ {\isadigit{1}}\ {\isasymdots}\ i\isactrlsub {\isadigit{2}}{\isachardoublequote}}
-  to assumption 2, and so on.
+  substitutions in the assumptions. The positions refer to the
+  assumptions in order from left to right.  For example, given in a
+  goal of the form \isa{{\isachardoublequote}P\ {\isacharparenleft}a\ {\isacharplus}\ b{\isacharparenright}\ {\isasymLongrightarrow}\ P\ {\isacharparenleft}c\ {\isacharplus}\ d{\isacharparenright}\ {\isasymLongrightarrow}\ {\isasymdots}{\isachardoublequote}}, position 1 of
+  commutativity of \isa{{\isachardoublequote}{\isacharplus}{\isachardoublequote}} is the subterm \isa{{\isachardoublequote}a\ {\isacharplus}\ b{\isachardoublequote}} and
+  position 2 is the subterm \isa{{\isachardoublequote}c\ {\isacharplus}\ d{\isachardoublequote}}.
 
   \item [\hyperlink{method.hypsubst}{\mbox{\isa{hypsubst}}}] performs substitution using some
   assumption; this only works for equations of the form \isa{{\isachardoublequote}x\ {\isacharequal}\ t{\isachardoublequote}} where \isa{x} is a free or bound variable.




