I'd argue for the converse: Computer Science is Mathematics
The space of programs is arguably larger than the space of mathematical systems, because programs can be logically inconsistent. This suggests that mathematics is a logically consistent subset of computer science, not the other way around.
Lisp? Knuth and computation? Lambda Calculus did it before. ] https://en.m.wikipedia.org/wiki/Lambda_calculus
And, before computers, we had these: