Namespace FStar.Mul cannot be found

[JansthcirlU]

Hi all, I installed the F* Windows binaries through the latest release, downloading it to C:\Program Files\fstar and adding the bin path to my environment variable. I then started working on the first Sample tutorial and the extension correctly called the fstar executable until I tried to open FStar.Mul to use the * as multiplication.

Here's what my code looks like:

module Sample

let incr (x:int) : int = x + 1
let incr1 (x:int) : y:int{y > x} = x + 1
// let incr2 (x:int) : nat = x + 1
let incr3 (x:nat) : nat = x + 1

val incr4 (x:int{x >= -2}) : y:int{y >= -1}
let incr4 x = x + 1

// Max
val max (x:int) (y:int) : z:int{if x >= y then z = x else z = y}
let max x y = if x >= y then x else y

open FStar.Mul (* - Namespace FStar.Mul cannot be found *)

let rec factorial (n:nat) : nat =
    if n = 0
    then 1
    else n * factorial (n - 1)

But when I manually run fstar Sample.fst, code verification happens without errors.

What could the problem be and how could I resolve it?

[JansthcirlU]

Reloading my VS Code editor a number of times fixes the issue sometimes, but it's not very consistent.