( c-addr1 u1 c-addr2 u2
Set the string c-addr1 u1
as the text to substitute for
the substitution named by c-addr2 u2
If the substitution does not exist it is created.
The program may then reuse the buffer c-addr1 u1
affecting the definition of the substitution.
Ambiguous conditions occur as follows:
- The substitution cannot be created;
- The name of a substitution contains the `
%' delimiter character.
may allot data space and create a definition. This breaks
the contiguity of the current region and is not allowed during compilation
of a colon definition