fc syntax notes

You can use a negative number to specify an event relative to the current command-line

Defaults

EDITOR_NAME:

The editor to be used is specified in the EDITOR_NAME argument. If EDITOR_NAME is not given, the value in the shell parameter FCEDIT is used.

first and last:

You can use a negative number to specify an event number relative to the current event number.

With no explicit value set, first defaults to '-1' (most recent command), and last defaults to the value of first.

However, if just printing commands with the -l flag, first defaults to '-16' and last defaults to '-1'. (Prints the last 16 commands)