彼の自叙伝が今日発売され、午前中に完売した。
His autobiography was released today and was sold out by noon.

不定詞の形容詞的用法には２種類あり、1 限定用法、2 叙述用法。2 はもちろん主格補語です。
There are two ways of using the infinitive as an adjective, 1. attributive, 2. predicative. Naturally 2. is a subject complement.

私は叙事詩よりも叙情詩の方が好きだ。
I like lyric better than epic.