Man pages matching name vector_length in section 3alleg4:

vector_length.3alleg4.en	debian 10 / allegro4-doc
vector_length.3alleg4.en	debian 11 / allegro4-doc
vector_length.3alleg4.en	debian 12 / allegro4-doc
vector_length.3alleg4.en	debian 13 / allegro4-doc