>the word "function" entails "operation", which entails "time"

Pure functions do not. Pure functions are relations from a domain to a codomain, implying a "mapping", but not an "operation", which I believe implies change. This mapping (from the domain to the codomain) can be presented as a subset of the cartesian product of the domain by the codomain (which you allude to.) This is devoid of any notion of "time".