There are two modes:   command and edit.    Some commands work in either

Command mode                            edit mode

<cr>    go into edit mode               <cr> leave edit mode and execute cmd
/n      execute command n (1..7)        ^z   leave edit mode (don't execute)
^y      interupt so one can exit        /n   retreive n'th
\       enter editor with 7 cmds        a_b  change `a' to `b'
					=x   define x to be current string
Either mode                             a_   delete `a'
                                        _b   insert `b'
/       display saved commands          _    delete all text
?       display this text               a    append a
^y      interupt (restart sh)
^y^y    exit
