siong-iok相約

to agree

to agree (on meeting place, date, etc.); to reach an agreement; to make an appointment; to cancel

mathematics

English Wiktionary, “相約” (CC BY-SA 4.0) — https://en.wiktionary.org/wiki/%E7%9B%B8%E7%B4%84 · confidence: Medium (Wiktionary, Hokkien)