TLA+ = formal language for modeling software above the code level and hardware above the circuit level by Leslie Lamport (of vector clock and Paxos fame, among other things.) https://lamport.azurewebsites.net/tla/tla.html
So there's \in, \subseteq and probably many others that are written just like in Latex. Notably \cap and \cup were also copied from Latex, which describe the shape of the symbol instead of its meaning. But not \to, \mapsto, \Vee and \Wedge, they're written as ASCII art ->, |->, \/ and /\. Then there's SUBSET, which means power set ... yeah. -_-
If the LaTeX-like syntax worries you, several projects aimed at providing PL-like syntaxes for TLA+. They vary by their degree of how much of the logic they throw away. I am not going to advertise these projects here, but you would find them on GitHub search by typing the tags like "#tlaplus #language", "#tlaplus #library", and "#tlaplus #pluscal".