等价

equal / equal in value / equivalent

class / rank / grade / equal to / same as / to wait for / to await / et cetera / and so on / et al. (and other authors) / after / as soon as / once

price / value / (chemistry) valence

great / good / middleman / servant

equal-value exchange

equivalence relation (math.)

exchange of unequal values

(math.) equivalence relation