Function: ps-extend-face-list

Extend face in ALIST-SYM.

If optional MERGE-P is non-nil, extensions in FACE-EXTENSION-LIST are merged
with face extension in ALIST-SYM; otherwise, overrides.

If optional ALIST-SYM is nil, `ps-print-face-extension-alist' is used;
otherwise, it should be an alist symbol.

The elements in FACE-EXTENSION-LIST are like those for `ps-extend-face'.

See `ps-extend-face' for documentation.

(fn FACE-EXTENSION-LIST &optional MERGE-P ALIST-SYM)