The phrase "a function that was" is correct and usable in written English.
It can be used when referring to a specific function that existed or was defined in the past.
Example: "The software update included a function that was designed to improve performance."
Alternatives: "a function that existed" or "a function that had been".
I once spoke at a function that was almost entirely male and began by saying, 'Here comes diversity.' Cue nervous laughter".
With Anonymous, he fulfilled a function that was necessary, and which few others were willing to do: put a public face to a movement for transparency.
The theatre became an important means of arousing patriotic fervour, a function that was to continue well into the 19th century.
As they ascended the social scale, heralds began to serve as ambassadors between the different courts, a function that was still theirs in the first half of the 17th century.
Interestingly, in a recent study sublingual iDCs were shown to be dispensable in eliciting tolerance against ovalbumin, a function that was mediated by oral macrophage-like (CD11b+CD11c−) cells.36 It is thus likely that in a mouse model sublingual iDCs primarily induce immunity, whereas CD11b+CD11c− cells are involved in mediating tolerance.
At TerraCycle, which is a fast-growing company, the people who have received substantial raises, moving from making $30,000 to more than three times that per year in a relatively short period of time, are those who not only did great work but took on significantly more responsibility and as such performed a function that was worth more to the organization.
A function that is contained within a class definition.
Desmin also controls nuclei and mitochondria positioning, a function that is altered by mutations in MTM145.
It's a function that's currently lacking in any other smart assistant, most notably Amazon's Alexa.
These genes may have a function that is closely related to Polycomb silencing, either directly or indirectly.
