Some operators require parentheses

```fstar
module OpAmpDot
open Pulse.Nolib
#lang-pulse

let op_Amp_Dot a b = a * b

fn foo (a b: int) returns int {
// The following breaks without parentheses:
a &. b // - Syntax error
}
```

Start with the minimal Pulse example in the issue, especially `a &. b` inside `foo`, and compare it with the parenthesized form. Trace how this operator is parsed and confirm the example succeeds without parentheses when the issue is fixed.

Written by the indexing model from the issue text.