If the Echo option is on, then the system echoes every command at the
top level. When logging a CoCoA session, one would set Echo to TRUE
in order to log both the input as well as the output in a CoCoA
session (see OpenLog).
Example
1+1;
2
-------------------------------
Set Echo;
1+1;
1 + 1
2
-------------------------------
L := [1,2,3];
L := [1, 2, 3]
Unset Echo;
SET(Echo, FALSE)
L := [4,5,6];
-------------------------------