Informally, an edit script gives a sequence of edit operations that
transforms one tree into another. Formally, we say when is the result of applying
the edit operation to . Given a sequence of edit operations, we say if there exist such that . A sequence **E** of edit
operations *transforms* into if and is isomorphic to
. (Recall that two trees are isomorphic if they differ only in
the identifiers of their nodes.) We call such a sequence of edit
operations an *edit script of with respect to *.
Notice that an edit script does not tell us how the original matching
between and should be modified to obtain the total
matching between and . This will be done as the edit
script is generated; see Section 4.

**:** Applying the edit script of Example 3.1

Wed Jun 19 08:22:34 PDT 1996