That's one use, yes, but it isn't the only use. And it's certainly not why they were invented Typed lambda calculus was formalized before the first programmabl

That's one use, yes, but it isn't the only use. And it's certainly not why they were invented Typed lambda calculus was formalized before the first programmable computers, and it's relation to programming wasn't clarified for another 20+ years (and real type systems don't really start to appear in programming languages for another decade after that afaik).