Looks SDF-ish. My guess is convert the letters to curves, cut them into pieces without holes so each piece is the set of points between certain curves, write down SDFs for each curve (negative on the "inside", positive on the "outside"), combine all SDFs in a piece with intersection (max), then combine all pieces with union (min).
the text contains a math expression. The math expression can be interpreted as an abstract syntax tree. The AST can also be translated into bytecode and interpreted by a stack-based virtual machine.