scroll-down-command

scroll-down-command is an interactive compiled Lisp function in `window.el'.

It is bound to <prior>, M-v.

(scroll-down-command &optional ARG)

Scroll text of selected window down ARG lines; or near full screen if no ARG.
If `scroll-error-top-bottom' is non-nil and `scroll-down' cannot
scroll window further, move cursor to the top line.
When point is already on that position, then signal an error.
A near full screen is `next-screen-context-lines' less than a full screen.
Negative ARG means scroll upward.
If ARG is the atom `-', scroll upward by nearly full screen.