The way I always think about it is in terms of scope. With: let x = v in expr `x` is now available for use in `expr` In essence, an OCaml program is a gian

The way I always think about it is in terms of scope. With: let x = v in expr `x` is now available for use in `expr` In essence, an OCaml program is a giant recursive expression, because `expr` can have its own set of let definitions. In the REPL, this is where the double semicolons come in, as a sort of hint to continue processing after the expression.