What do you mean by "Medieval math notation"? Wasn't it mostly just textual descriptions? (which arguably would not be too far away from the natural language being used to interact with LLMs)
It wasn't until Thomas Harriot's _Artis Analyticae Praxis_ was published that one got anything resembling consistent math notation as folks today would expect, and isn't the symbology used for APL just a formalization and/or extension of prevailing math symbol usage? (which was the point of the whole thing?)
You are correct, most modern mathematical notation emerged during the Renaissance and Early Modern periods (late 15th-18th centuries). Indeed before that was rhetorical.
It wasn't until Thomas Harriot's _Artis Analyticae Praxis_ was published that one got anything resembling consistent math notation as folks today would expect, and isn't the symbology used for APL just a formalization and/or extension of prevailing math symbol usage? (which was the point of the whole thing?)