--- a/doc-src/TutorialI/Rules/rules.tex Mon Apr 16 15:34:33 2001 +0200
+++ b/doc-src/TutorialI/Rules/rules.tex Tue Apr 17 15:03:41 2001 +0200
@@ -50,7 +50,7 @@
consequences from this symbol. Ideally each rule should mention
one symbol only. For predicate logic this can be
done, but when users define their own concepts they typically
-have to refer to other symbols as well. It is best not be dogmatic.
+have to refer to other symbols as well. It is best not to be dogmatic.
Natural deduction generally deserves its name. It is easy to use. Each
proof step consists of identifying the outermost symbol of a formula and