[closeparen]

We wrote some programs in lambda calculus, but I mainly remember working on an ML interpreter. Type checking, exceptions, free variables, etc.

[mcguire]

"Historically, ML was conceived to develop proof tactics in the LCF theorem prover (whose language, pplambda, a combination of the first-order predicate calculus and the simply-typed polymorphic lambda calculus, had ML as its metalanguage)."

-- https://en.wikipedia.org/wiki/ML_(programming_language)