🚀 go-pugleaf

In GNU Emacs 19.25.1 of Thu Jun 30 1994 on mathserv (sparc-sun-solaris2.3)

Example:
(define-key function-key-map  "\C-x\C-a1" "\C-x\C-a2")
"
2"
(define-key function-key-map  "\C-x\C-a2" [left])
[left]
(read-key-sequence "") ; C-xC-a2
[left]
(read-key-sequence "") ; C-xC-a1
"
2"

i would expect to get [left] as an answer.

Why this is bad? I redefine kp-7 as 7 (or is it the standard, I do not
remember), and VT100 redefined \eOw as kp-7. However, \eOw does not
work as 7, moreover, on C-h c ESC O w
it answers `kp-7 is undefined', that is not the complete truth,
since under X it recognizes the key that sends this code.

Confusion is amplified by the fact that documentation describes
function-key-map as transitive (or maybe my reading is wrong?).

Best regards,
Ilya